diff --git a/src/cpuprofiler.js b/src/cpuprofiler.js
index 6d0393584eba4..f8f919431afed 100644
--- a/src/cpuprofiler.js
+++ b/src/cpuprofiler.js
@@ -580,7 +580,7 @@ var emscriptenCpuProfiler = {
     var realf = 'real_' + f;
     glCtx[realf] = glCtx[f];
     var numArgs = this.webGLFunctionLength(f); // On Firefox & Chrome, could do "glCtx[realf].length", but that doesn't work on Edge, which always reports 0.
-    // Accessing 'arguments' is super slow, so to avoid overhead, statically reason the number of arguments.
+    // Accessing 'arguments'/'...' is super slow, so to avoid overhead, statically reason the number of arguments.
     switch (numArgs) {
       case 0: glCtx[f] = () => { this.enterSection(section); var ret = glCtx[realf](); this.endSection(section); return ret; }; break;
       case 1: glCtx[f] = (a1) => { this.enterSection(section); var ret =  glCtx[realf](a1); this.endSection(section); return ret; }; break;
diff --git a/src/embind/embind.js b/src/embind/embind.js
index a7147b4124858..bee7627b4c9a0 100644
--- a/src/embind/embind.js
+++ b/src/embind/embind.js
@@ -98,12 +98,12 @@ var LibraryEmbind = {
     if (undefined === proto[methodName].overloadTable) {
       var prevFunc = proto[methodName];
       // Inject an overload resolver function that routes to the appropriate overload based on the number of arguments.
-      proto[methodName] = function() {
+      proto[methodName] = function(...args) {
         // TODO This check can be removed in -O3 level "unsafe" optimizations.
-        if (!proto[methodName].overloadTable.hasOwnProperty(arguments.length)) {
-            throwBindingError(`Function '${humanName}' called with an invalid number of arguments (${arguments.length}) - expects one of (${proto[methodName].overloadTable})!`);
+        if (!proto[methodName].overloadTable.hasOwnProperty(args.length)) {
+            throwBindingError(`Function '${humanName}' called with an invalid number of arguments (${args.length}) - expects one of (${proto[methodName].overloadTable})!`);
         }
-        return proto[methodName].overloadTable[arguments.length].apply(this, arguments);
+        return proto[methodName].overloadTable[args.length].apply(this, args);
       };
       // Move the previous function into the overload table.
       proto[methodName].overloadTable = [];
@@ -818,9 +818,9 @@ var LibraryEmbind = {
     var argsWired = new Array(expectedArgCount);
     var invokerFuncArgs = [];
     var destructors = [];
-    var invokerFn = function() {
-      if (arguments.length !== expectedArgCount) {
-        throwBindingError(`function ${humanName} called with ${arguments.length} arguments, expected ${expectedArgCount}`);
+    var invokerFn = function(...args) {
+      if (args.length !== expectedArgCount) {
+        throwBindingError(`function ${humanName} called with ${args.length} arguments, expected ${expectedArgCount}`);
       }
 #if EMSCRIPTEN_TRACING
       Module.emscripten_trace_enter_context(`embind::${humanName}`);
@@ -834,11 +834,11 @@ var LibraryEmbind = {
         invokerFuncArgs[1] = thisWired;
       }
       for (var i = 0; i < expectedArgCount; ++i) {
-        argsWired[i] = argTypes[i + 2]['toWireType'](destructors, arguments[i]);
+        argsWired[i] = argTypes[i + 2]['toWireType'](destructors, args[i]);
         invokerFuncArgs.push(argsWired[i]);
       }
 
-      var rv = cppInvokerFunc.apply(null, invokerFuncArgs);
+      var rv = cppInvokerFunc(...invokerFuncArgs);
 
       function onDone(rv) {
         if (needsDestructorStack) {
@@ -896,11 +896,11 @@ var LibraryEmbind = {
 
 #if EMBIND_AOT
   var signature = createJsInvokerSignature(argTypes, isClassMethodFunc, returns, isAsync);
-  var invokerFn = InvokerFunctions[signature].apply(null, closureArgs);
+  var invokerFn = InvokerFunctions[signature](...closureArgs);
 #else
   let [args, invokerFnBody] = createJsInvoker(argTypes, isClassMethodFunc, returns, isAsync);
   args.push(invokerFnBody);
-  var invokerFn = newFunc(Function, args).apply(null, closureArgs);
+  var invokerFn = newFunc(Function, args)(...closureArgs);
 #endif
 #endif
     return createNamedFunction(humanName, invokerFn);
@@ -1765,18 +1765,18 @@ var LibraryEmbind = {
           basePrototype = ClassHandle.prototype;
         }
 
-        var constructor = createNamedFunction(name, function() {
+        var constructor = createNamedFunction(name, function(...args) {
           if (Object.getPrototypeOf(this) !== instancePrototype) {
             throw new BindingError("Use 'new' to construct " + name);
           }
           if (undefined === registeredClass.constructor_body) {
             throw new BindingError(name + " has no accessible constructor");
           }
-          var body = registeredClass.constructor_body[arguments.length];
+          var body = registeredClass.constructor_body[args.length];
           if (undefined === body) {
-            throw new BindingError(`Tried to invoke ctor of ${name} with invalid number of parameters (${arguments.length}) - expected (${Object.keys(registeredClass.constructor_body).toString()}) parameters instead!`);
+            throw new BindingError(`Tried to invoke ctor of ${name} with invalid number of parameters (${args.length}) - expected (${Object.keys(registeredClass.constructor_body).toString()}) parameters instead!`);
           }
-          return body.apply(this, arguments);
+          return body.apply(this, args);
         });
 
         var instancePrototype = Object.create(basePrototype, {
@@ -2197,14 +2197,12 @@ var LibraryEmbind = {
     wrapperType = requireRegisteredType(wrapperType, 'wrapper');
     properties = Emval.toValue(properties);
 
-    var arraySlice = [].slice;
-
     var registeredClass = wrapperType.registeredClass;
     var wrapperPrototype = registeredClass.instancePrototype;
     var baseClass = registeredClass.baseClass;
     var baseClassPrototype = baseClass.instancePrototype;
     var baseConstructor = registeredClass.baseClass.constructor;
-    var ctor = createNamedFunction(constructorName, function() {
+    var ctor = createNamedFunction(constructorName, function(...args) {
       registeredClass.baseClass.pureVirtualFunctions.forEach(function(name) {
         if (this[name] === baseClassPrototype[name]) {
           throw new PureVirtualError(`Pure virtual function ${name} must be implemented in JavaScript`);
@@ -2214,19 +2212,17 @@ var LibraryEmbind = {
       Object.defineProperty(this, '__parent', {
         value: wrapperPrototype
       });
-      this["__construct"].apply(this, arraySlice.call(arguments));
+      this["__construct"](...args);
     });
 
     // It's a little nasty that we're modifying the wrapper prototype here.
 
-    wrapperPrototype["__construct"] = function __construct() {
+    wrapperPrototype["__construct"] = function __construct(...args) {
       if (this === wrapperPrototype) {
         throwBindingError("Pass correct 'this' to __construct");
       }
 
-      var inner = baseConstructor["implement"].apply(
-        undefined,
-        [this].concat(arraySlice.call(arguments)));
+      var inner = baseConstructor["implement"](this, ...args);
       detachFinalizer(inner);
       var $$ = inner.$$;
       inner["notifyOnDestruction"]();
diff --git a/src/embind/emval.js b/src/embind/emval.js
index 174834aa64a3c..ce221c174685b 100644
--- a/src/embind/emval.js
+++ b/src/embind/emval.js
@@ -369,7 +369,7 @@ var LibraryEmVal = {
       "};\n";
 
     params.push(functionBody);
-    var invokerFunction = newFunc(Function, params).apply(null, args);
+    var invokerFunction = newFunc(Function, params)(...args);
 #endif
     var functionName = `methodCaller<(${types.map(t => t.name).join(', ')}) => ${retType.name}>`;
     return emval_addMethodCaller(createNamedFunction(functionName, invokerFunction));
diff --git a/src/jsifier.js b/src/jsifier.js
index 50a8256cc33ab..02580d0befe13 100644
--- a/src/jsifier.js
+++ b/src/jsifier.js
@@ -238,9 +238,9 @@ ${argConvertions}
     if (LIBRARY_DEBUG && !isJsOnlySymbol(symbol)) {
       snippet = modifyJSFunction(snippet, (args, body, async) => `\
 function(${args}) {
-  var ret = (function() { if (runtimeDebug) err("[library call:${mangled}: " + Array.prototype.slice.call(arguments).map(prettyPrint) + "]");
+  var ret = (() => { if (runtimeDebug) err("[library call:${mangled}: " + Array.prototype.slice.call(arguments).map(prettyPrint) + "]");
   ${body}
-  }).apply(this, arguments);
+  })();
   if (runtimeDebug && typeof ret != "undefined") err("  [     return:" + prettyPrint(ret));
   return ret;
 }`);
@@ -444,8 +444,8 @@ function(${args}) {
           if (ASSERTIONS) {
             assertion += `if (!${target} || ${target}.stub) abort("external symbol '${symbol}' is missing. perhaps a side module was not linked in? if this function was expected to arrive from a system library, try to build the MAIN_MODULE with EMCC_FORCE_STDLIBS=1 in the environment");\n`;
           }
-          const functionBody = assertion + `return ${target}.apply(null, arguments);`;
-          LibraryManager.library[symbol] = new Function(functionBody);
+          const functionBody = assertion + `return ${target}(...args);`;
+          LibraryManager.library[symbol] = new Function('...args', functionBody);
           isStub = true;
         }
       }
diff --git a/src/library.js b/src/library.js
index 135c734fc0aa6..88cc447b59859 100644
--- a/src/library.js
+++ b/src/library.js
@@ -2874,7 +2874,7 @@ addToLibrary({
 #if ASSERTIONS
     assert(ASM_CONSTS.hasOwnProperty(code), `No EM_ASM constant found at address ${code}.  The loaded WebAssembly file is likely out of sync with the generated JavaScript.`);
 #endif
-    return ASM_CONSTS[code].apply(null, args);
+    return ASM_CONSTS[code](...args);
   },
 
   emscripten_asm_const_int__deps: ['$runEmAsmFunction'],
@@ -2917,7 +2917,7 @@ addToLibrary({
 #if ASSERTIONS
     assert(ASM_CONSTS.hasOwnProperty(code), `No EM_ASM constant found at address ${code}.  The loaded WebAssembly file is likely out of sync with the generated JavaScript.`);
 #endif
-    return ASM_CONSTS[code].apply(null, args);
+    return ASM_CONSTS[code](...args);
   },
   emscripten_asm_const_int_sync_on_main_thread__deps: ['$runMainThreadEmAsm'],
   emscripten_asm_const_int_sync_on_main_thread: (code, sigPtr, argbuf) => {
@@ -3100,7 +3100,7 @@ addToLibrary({
 #endif
     var f = Module['dynCall_' + sig];
 #endif
-    return args && args.length ? f.apply(null, [ptr].concat(args)) : f.call(null, ptr);
+    return f(ptr, ...args);
   },
   $dynCall__deps: ['$dynCallLegacy', '$getWasmTableEntry'],
 #endif
@@ -3113,16 +3113,10 @@ addToLibrary({
 #if ASSERTIONS && !DYNCALLS
     assert(sig.includes('j') || sig.includes('p'), 'getDynCaller should only be called with i64 sigs')
 #endif
-    var argCache = [];
-    return function() {
-      argCache.length = 0;
-      Object.assign(argCache, arguments);
-      return dynCall(sig, ptr, argCache);
-    };
+    return (...args) => dynCall(sig, ptr, args);
   },
 
-  $dynCall__docs: '/** @param {Object=} args */',
-  $dynCall: (sig, ptr, args) => {
+  $dynCall: (sig, ptr, args = []) => {
 #if MEMORY64
     // With MEMORY64 we have an additional step to convert `p` arguments to
     // bigint. This is the runtime equivalent of the wrappers we create for wasm
@@ -3145,7 +3139,7 @@ addToLibrary({
 #if ASSERTIONS
     assert(getWasmTableEntry(ptr), `missing table entry in dynCall: ${ptr}`);
 #endif
-    var rtn = getWasmTableEntry(ptr).apply(null, args);
+    var rtn = getWasmTableEntry(ptr)(...args);
 #endif
 #if MEMORY64
     return sig[0] == 'p' ? Number(rtn) : rtn;
diff --git a/src/library_addfunction.js b/src/library_addfunction.js
index 4b752088d909a..e9fa8f2adb9f6 100644
--- a/src/library_addfunction.js
+++ b/src/library_addfunction.js
@@ -117,7 +117,7 @@ addToLibrary({
     ];
     // Write the overall length of the type section followed by the body
     uleb128Encode(typeSectionBody.length, bytes);
-    bytes.push.apply(bytes, typeSectionBody);
+    bytes.push(...typeSectionBody);
 
     // The rest of the module is static
     bytes.push(
diff --git a/src/library_async.js b/src/library_async.js
index 91fb42c75ff09..c9bda2cc97c93 100644
--- a/src/library_async.js
+++ b/src/library_async.js
@@ -68,10 +68,10 @@ addToLibrary({
           }
 #endif
 #if ASSERTIONS && ASYNCIFY != 2 // We cannot apply assertions with stack switching, as the imports must not be modified from suspender.suspendOnReturnedPromise TODO find a way
-          imports[x] = function() {
+          imports[x] = (...args) => {
             var originalAsyncifyState = Asyncify.state;
             try {
-              return original.apply(null, arguments);
+              return original(...args);
             } finally {
               // Only asyncify-declared imports are allowed to change the
               // state.
@@ -130,7 +130,7 @@ addToLibrary({
             original = Asyncify.makeAsyncFunction(original);
           }
 #endif
-          ret[x] = function() {
+          ret[x] = (...args) => {
 #if ASYNCIFY_DEBUG >= 2
             dbg(`ASYNCIFY: ${'  '.repeat(Asyncify.exportCallStack.length} try ${x}`);
 #endif
@@ -143,9 +143,9 @@ addToLibrary({
               // can just call the function with no args at all since and the engine will produce zeros
               // for all arguments.  However, for i64 arguments we get `undefined cannot be converted to
               // BigInt`.
-              return original.apply(null, Asyncify.saveOrRestoreRewindArguments(x, arguments));
+              return original(...Asyncify.saveOrRestoreRewindArguments(x, args));
 #else
-              return original.apply(null, arguments);
+              return original(...args);
 #endif
 #if ASYNCIFY == 1
             } finally {
diff --git a/src/library_ccall.js b/src/library_ccall.js
index f90caf0039a87..0eedb39017e3c 100644
--- a/src/library_ccall.js
+++ b/src/library_ccall.js
@@ -77,7 +77,7 @@ addToLibrary({
     // Data for a previous async operation that was in flight before us.
     var previousAsync = Asyncify.currData;
 #endif
-    var ret = func.apply(null, cArgs);
+    var ret = func(...cArgs);
     function onDone(ret) {
 #if ASYNCIFY == 1
       runtimeKeepalivePop();
diff --git a/src/library_dylink.js b/src/library_dylink.js
index 7c449378df2b1..38fb24852922d 100644
--- a/src/library_dylink.js
+++ b/src/library_dylink.js
@@ -707,9 +707,9 @@ var LibraryDylink = {
           // when first called.
           if (!(prop in stubs)) {
             var resolved;
-            stubs[prop] = function() {
+            stubs[prop] = (...args) => {
               resolved ||= resolveSymbol(prop);
-              return resolved.apply(null, arguments);
+              return resolved(...args);
             };
           }
           return stubs[prop];
diff --git a/src/library_fs.js b/src/library_fs.js
index 71566c744dfd7..16ff91ef04c23 100644
--- a/src/library_fs.js
+++ b/src/library_fs.js
@@ -513,7 +513,7 @@ FS.staticInit();` +
 
         mounts.push(m);
 
-        check.push.apply(check, m.mounts);
+        check.push(...m.mounts);
       }
 
       return mounts;
@@ -1784,9 +1784,9 @@ FS.staticInit();` +
       var keys = Object.keys(node.stream_ops);
       keys.forEach((key) => {
         var fn = node.stream_ops[key];
-        stream_ops[key] = function forceLoadLazyFile() {
+        stream_ops[key] = (...args) => {
           FS.forceLoadFile(node);
-          return fn.apply(null, arguments);
+          return fn(...args);
         };
       });
       function writeChunks(stream, buffer, offset, length, position) {
diff --git a/src/library_glemu.js b/src/library_glemu.js
index 18a88a8c68446..b5cf3001c2db6 100644
--- a/src/library_glemu.js
+++ b/src/library_glemu.js
@@ -3580,7 +3580,7 @@ var LibraryGLEmulation = {
         _glEnableVertexAttribArray(vaa);
       }
       for (var vaa in info.vertexAttribPointers) {
-        _glVertexAttribPointer.apply(null, info.vertexAttribPointers[vaa]);
+        _glVertexAttribPointer(...info.vertexAttribPointers[vaa]);
       }
       for (var attrib in info.enabledClientStates) {
         _glEnableClientState(attrib|0);
diff --git a/src/library_html5.js b/src/library_html5.js
index 478116eb831d0..eff2402afde4f 100644
--- a/src/library_html5.js
+++ b/src/library_html5.js
@@ -140,7 +140,7 @@ var LibraryHTML5 = {
         var call = JSEvents.deferredCalls[i];
         JSEvents.deferredCalls.splice(i, 1);
         --i;
-        call.targetFunction.apply(null, call.argsList);
+        call.targetFunction(...call.argsList);
       }
     },
 #endif
diff --git a/src/library_idbfs.js b/src/library_idbfs.js
index 30856cd3fec3e..7a670928aab6d 100644
--- a/src/library_idbfs.js
+++ b/src/library_idbfs.js
@@ -21,10 +21,8 @@ addToLibrary({
     },
     DB_VERSION: 21,
     DB_STORE_NAME: 'FILE_DATA',
-    mount: function(mount) {
-      // reuse all of the core MEMFS functionality
-      return MEMFS.mount.apply(null, arguments);
-    },
+    // reuse all of the core MEMFS functionality
+    mount: (...args) => MEMFS.mount(...args),
     syncfs: (mount, populate, callback) => {
       IDBFS.getLocalSet(mount, (err, local) => {
         if (err) return callback(err);
@@ -110,7 +108,7 @@ addToLibrary({
         }
 
         if (FS.isDir(stat.mode)) {
-          check.push.apply(check, FS.readdir(path).filter(isRealDir).map(toAbsolute(path)));
+          check.push(...FS.readdir(path).filter(isRealDir).map(toAbsolute(path)));
         }
 
         entries[path] = { 'timestamp': stat.mtime };
diff --git a/src/library_makeDynCall.js b/src/library_makeDynCall.js
index 65cba3366cbe8..7bda8276c0c06 100644
--- a/src/library_makeDynCall.js
+++ b/src/library_makeDynCall.js
@@ -31,7 +31,7 @@ addToLibrary({
 
     var typeSection = [0x01 /* Type section code */];
     uleb128Encode(typeSectionBody.length, typeSection); // length of section in bytes
-    typeSection.push.apply(typeSection, typeSectionBody);
+    typeSection.push(...typeSectionBody);
     sections.push(typeSection);
 
     var importSection = [
@@ -133,10 +133,10 @@ if (sig[0] === "j") {
 
     var codeBody = [0x01]; // one code
     uleb128Encode(convert_code.length, codeBody);
-    codeBody.push.apply(codeBody, convert_code);
+    codeBody.push(...convert_code);
     var codeSection = [0x0A /* Code section code */];
     uleb128Encode(codeBody.length, codeSection);
-    codeSection.push.apply(codeSection, codeBody);
+    codeSection.push(...codeBody);
     sections.push(codeSection);
 
     var bytes = new Uint8Array([].concat.apply([], sections));
diff --git a/src/library_math.js b/src/library_math.js
index c971124f4db68..72ad04b7f5e35 100644
--- a/src/library_math.js
+++ b/src/library_math.js
@@ -26,7 +26,7 @@ addToLibrary({
     for (var i = 0; i < count; ++i) {
       args.push({{{ makeGetValue('varargs', `i * ${getNativeTypeSize('double')}`, 'double') }}});
     }
-    return Math.hypot.apply(null, args);
+    return Math.hypot(...args);
   },
   emscripten_math_sin: (x) => Math.sin(x),
   emscripten_math_sinh: (x) => Math.sinh(x),
diff --git a/src/library_nodefs.js b/src/library_nodefs.js
index 177c57ca6958b..81864ffcc956f 100644
--- a/src/library_nodefs.js
+++ b/src/library_nodefs.js
@@ -87,7 +87,7 @@ addToLibrary({
       }
       parts.push(node.mount.opts.root);
       parts.reverse();
-      return PATH.join.apply(null, parts);
+      return PATH.join(...parts);
     },
     // This maps the integer permission modes from http://linux.die.net/man/3/open
     // to node.js-specific file open permission strings at http://nodejs.org/api/fs.html#fs_fs_open_path_flags_mode_callback
diff --git a/src/library_nodepath.js b/src/library_nodepath.js
index 4e817f43ed06a..c42820f36e289 100644
--- a/src/library_nodepath.js
+++ b/src/library_nodepath.js
@@ -17,9 +17,7 @@ addToLibrary({
     normalize: (path) => nodePath['normalize'](path),
     dirname: (path) => nodePath['dirname'](path),
     basename: (path) => nodePath['basename'](path),
-    join: function () {
-      return nodePath['join'].apply(null, arguments);
-    },
+    join: (...args) => nodePath['join'](...args),
     join2: (l, r) => nodePath['join'](l, r),
   },
   // The FS-using parts are split out into a separate object, so simple path
@@ -27,10 +25,9 @@ addToLibrary({
   $PATH_FS__deps: ['$FS'],
   $PATH_FS__docs: '/** @type{{resolve: function(...*)}} */',
   $PATH_FS: {
-    resolve: function () {
-      var paths = Array.prototype.slice.call(arguments, 0);
+    resolve: (...paths) => {
       paths.unshift(FS.cwd());
-      return nodePath['posix']['resolve'].apply(null, paths);
+      return nodePath['posix']['resolve'](...paths);
     },
     relative: (from, to) => nodePath['posix']['relative'](from || FS.cwd(), to || FS.cwd()),
   }
diff --git a/src/library_noderawfs.js b/src/library_noderawfs.js
index 15758d0e4d752..91f3b30fc9fbe 100644
--- a/src/library_noderawfs.js
+++ b/src/library_noderawfs.js
@@ -9,9 +9,9 @@ addToLibrary({
   $NODERAWFS__postset: `
     if (ENVIRONMENT_IS_NODE) {
       var _wrapNodeError = function(func) {
-        return function() {
+        return function(...args) {
           try {
-            return func.apply(this, arguments)
+            return func(...args)
           } catch (e) {
             if (e.code) {
               throw new FS.ErrnoError(ERRNO_CODES[e.code]);
@@ -52,7 +52,7 @@ addToLibrary({
     },
     // generic function for all node creation
     cwd() { return process.cwd(); },
-    chdir() { process.chdir.apply(void 0, arguments); },
+    chdir(...args) { process.chdir(...args); },
     mknod(path, mode) {
       if (FS.isDir(path)) {
         fs.mkdirSync(path, mode);
@@ -60,26 +60,26 @@ addToLibrary({
         fs.writeFileSync(path, '', { mode: mode });
       }
     },
-    mkdir() { fs.mkdirSync.apply(void 0, arguments); },
-    symlink() { fs.symlinkSync.apply(void 0, arguments); },
-    rename() { fs.renameSync.apply(void 0, arguments); },
-    rmdir() { fs.rmdirSync.apply(void 0, arguments); },
-    readdir() { return ['.', '..'].concat(fs.readdirSync.apply(void 0, arguments)); },
-    unlink() { fs.unlinkSync.apply(void 0, arguments); },
-    readlink() { return fs.readlinkSync.apply(void 0, arguments); },
-    stat() { return fs.statSync.apply(void 0, arguments); },
-    lstat() { return fs.lstatSync.apply(void 0, arguments); },
-    chmod() { fs.chmodSync.apply(void 0, arguments); },
+    mkdir(...args) { fs.mkdirSync(...args); },
+    symlink(...args) { fs.symlinkSync(...args); },
+    rename(...args) { fs.renameSync(...args); },
+    rmdir(...args) { fs.rmdirSync(...args); },
+    readdir(...args) { return ['.', '..'].concat(fs.readdirSync(...args)); },
+    unlink(...args) { fs.unlinkSync(...args); },
+    readlink(...args) { return fs.readlinkSync(...args); },
+    stat(...args) { return fs.statSync(...args); },
+    lstat(...args) { return fs.lstatSync(...args); },
+    chmod(...args) { fs.chmodSync(...args); },
     fchmod(fd, mode) {
       var stream = FS.getStreamChecked(fd);
       fs.fchmodSync(stream.nfd, mode);
     },
-    chown() { fs.chownSync.apply(void 0, arguments); },
+    chown(...args) { fs.chownSync(...args); },
     fchown(fd, owner, group) {
       var stream = FS.getStreamChecked(fd);
       fs.fchownSync(stream.nfd, owner, group);
     },
-    truncate() { fs.truncateSync.apply(void 0, arguments); },
+    truncate(...args) { fs.truncateSync(...args); },
     ftruncate(fd, len) {
       // See https://github.com/nodejs/node/issues/35632
       if (len < 0) {
diff --git a/src/library_path.js b/src/library_path.js
index 8f06d204d34e9..ab3112503a202 100644
--- a/src/library_path.js
+++ b/src/library_path.js
@@ -72,10 +72,7 @@ addToLibrary({
       if (lastSlash === -1) return path;
       return path.substr(lastSlash+1);
     },
-    join: function() {
-      var paths = Array.prototype.slice.call(arguments);
-      return PATH.normalize(paths.join('/'));
-    },
+    join: (...paths) => PATH.normalize(paths.join('/')),
     join2: (l, r) => PATH.normalize(l + '/' + r),
   },
   // The FS-using parts are split out into a separate object, so simple path
@@ -90,11 +87,11 @@ addToLibrary({
 #endif
   ],
   $PATH_FS: {
-    resolve: function() {
+    resolve: (...args) => {
       var resolvedPath = '',
         resolvedAbsolute = false;
-      for (var i = arguments.length - 1; i >= -1 && !resolvedAbsolute; i--) {
-        var path = (i >= 0) ? arguments[i] : FS.cwd();
+      for (var i = args.length - 1; i >= -1 && !resolvedAbsolute; i--) {
+        var path = (i >= 0) ? args[i] : FS.cwd();
         // Skip empty and invalid entries
         if (typeof path != 'string') {
           throw new TypeError('Arguments to path.resolve must be strings');
diff --git a/src/library_proxyfs.js b/src/library_proxyfs.js
index d234e2423fc46..b9b050dff8c4f 100644
--- a/src/library_proxyfs.js
+++ b/src/library_proxyfs.js
@@ -27,7 +27,7 @@ addToLibrary({
       }
       parts.push(node.mount.opts.root);
       parts.reverse();
-      return PATH.join.apply(null, parts);
+      return PATH.join(...parts);
     },
     node_ops: {
       getattr(node) {
diff --git a/src/library_pthread.js b/src/library_pthread.js
index b1497ff91a103..346484af7d79e 100644
--- a/src/library_pthread.js
+++ b/src/library_pthread.js
@@ -1040,7 +1040,7 @@ var LibraryPThread = {
     assert(func.length == numCallArgs, 'Call args mismatch in _emscripten_receive_on_main_thread_js');
 #endif
     PThread.currentProxiedOperationCallerThread = callingThread;
-    var rtn = func.apply(null, proxiedJSCallArgs);
+    var rtn = func(...proxiedJSCallArgs);
     PThread.currentProxiedOperationCallerThread = 0;
 #if MEMORY64
     // In memory64 mode some proxied functions return bigint/pointer but
diff --git a/src/library_sdl.js b/src/library_sdl.js
index de6695bfec90d..42eeb2a6e331e 100644
--- a/src/library_sdl.js
+++ b/src/library_sdl.js
@@ -2163,7 +2163,7 @@ var LibrarySDL = {
         var x = stackAlloc({{{ getNativeTypeSize('i32') }}});
         var y = stackAlloc({{{ getNativeTypeSize('i32') }}});
         var comp = stackAlloc({{{ getNativeTypeSize('i32') }}});
-        var data = Module['_' + func].apply(null, params.concat([x, y, comp, 0]));
+        var data = Module['_' + func](...params, x, y, comp, 0);
         if (!data) return null;
         addCleanup(() => Module['_stbi_image_free'](data));
         return {
diff --git a/src/parseTools.js b/src/parseTools.js
index 74137e35fbebe..6dfe78b605691 100644
--- a/src/parseTools.js
+++ b/src/parseTools.js
@@ -622,9 +622,9 @@ Please update to new syntax.`);
 
     const dyncall = `dynCall_${sig}`;
     if (sig.length > 1) {
-      return `((${args}) => ${dyncall}.apply(null, [${funcPtr}, ${callArgs}]))`;
+      return `((${args}) => ${dyncall}(${funcPtr}, ${callArgs}))`;
     }
-    return `(() => ${dyncall}.call(null, ${funcPtr}))`;
+    return `(() => ${dyncall}(${funcPtr}))`;
   }
 
   if (needArgConversion) {
diff --git a/src/preamble.js b/src/preamble.js
index 032eff4b8eeb8..c4f8022ec1236 100644
--- a/src/preamble.js
+++ b/src/preamble.js
@@ -513,14 +513,14 @@ Module['FS_createPreloadedFile'] = FS.createPreloadedFile;
 
 #if ASSERTIONS
 function createExportWrapper(name) {
-  return function() {
+  return (...args) => {
     assert(runtimeInitialized, `native function \`${name}\` called before runtime initialization`);
 #if EXIT_RUNTIME
     assert(!runtimeExited, `native function \`${name}\` called after runtime exit (use NO_EXIT_RUNTIME to keep it alive after main() exits)`);
 #endif
     var f = wasmExports[name];
     assert(f, `exported native function \`${name}\` not found`);
-    return f.apply(null, arguments);
+    return f(...args);
   };
 }
 #endif
@@ -537,7 +537,7 @@ var abortWrapperDepth = 0;
 
 // Creates a wrapper in a closure so that each wrapper gets it's own copy of 'original'
 function makeAbortWrapper(original) {
-  return function() {
+  return (...args) => {
     // Don't allow this function to be called if we're aborted!
     if (ABORT) {
       throw "program has already aborted!";
@@ -545,7 +545,7 @@ function makeAbortWrapper(original) {
 
     abortWrapperDepth += 1;
     try {
-      return original.apply(null, arguments);
+      return original(...args);
     } catch (e) {
       if (
         ABORT // rethrow exception if abort() was called in the original function call above
@@ -700,7 +700,7 @@ var wasmOffsetConverter;
 {{{ makeModuleReceiveWithVar('loadSplitModule', undefined, 'instantiateSync',  true) }}}
 var splitModuleProxyHandler = {
   get(target, prop, receiver) {
-    return function() {
+    return (...args) => {
 #if ASYNCIFY == 2
       throw new Error('Placeholder function "' + prop + '" should not be called when using JSPI.');
 #else
@@ -714,9 +714,9 @@ var splitModuleProxyHandler = {
       // When the table is dynamically laid out, the placeholder functions names
       // are offsets from the table base. In the main module, the table base is
       // always 1.
-      return wasmTable.get(1 + parseInt(prop)).apply(null, arguments);
+      return wasmTable.get(1 + parseInt(prop))(...args);
 #else
-      return wasmTable.get(prop).apply(null, arguments);
+      return wasmTable.get(prop)(...args);
 #endif
 #endif
     }
diff --git a/src/runtime_debug.js b/src/runtime_debug.js
index 0ade98dba7a68..d5082859671c3 100644
--- a/src/runtime_debug.js
+++ b/src/runtime_debug.js
@@ -161,16 +161,16 @@ function prettyPrint(arg) {
 
 #if ASSERTIONS || RUNTIME_DEBUG || AUTODEBUG
 // Used by XXXXX_DEBUG settings to output debug messages.
-function dbg(text) {
+function dbg(...args) {
 #if ENVIRONMENT_MAY_BE_NODE && PTHREADS
   // Avoid using the console for debugging in multi-threaded node applications
   // See https://github.com/emscripten-core/emscripten/issues/14804
   if (ENVIRONMENT_IS_NODE) {
-    fs.writeSync(2, Array.from(arguments).join(' ') + '\n');
+    fs.writeSync(2, args.join(' ') + '\n');
   } else
 #endif
   // TODO(sbc): Make this configurable somehow.  Its not always convenient for
   // logging to show up as warnings.
-  console.warn.apply(console, arguments);
+  console.warn(...args);
 }
 #endif
diff --git a/src/shell.html b/src/shell.html
index ad6e06097b42b..6a946c28d0c1d 100644
--- a/src/shell.html
+++ b/src/shell.html
@@ -38,8 +38,8 @@
         print: (function() {
           var element = document.getElementById('output');
           if (element) element.value = ''; // clear browser cache
-          return function(text) {
-            if (arguments.length > 1) text = Array.prototype.slice.call(arguments).join(' ');
+          return (...args) => {
+            var text = args.join(' ');
             // These replacements are necessary if you render to raw HTML
             //text = text.replace(/&/g, "&amp;");
             //text = text.replace(/</g, "&lt;");
diff --git a/src/shell_minimal.html b/src/shell_minimal.html
index 228b487595b95..871ccaf687a43 100644
--- a/src/shell_minimal.html
+++ b/src/shell_minimal.html
@@ -77,8 +77,8 @@
         print: (function() {
           var element = document.getElementById('output');
           if (element) element.value = ''; // clear browser cache
-          return function(text) {
-            if (arguments.length > 1) text = Array.prototype.slice.call(arguments).join(' ');
+          return (...args) => {
+            var text = args.join(' ');
             // These replacements are necessary if you render to raw HTML
             //text = text.replace(/&/g, "&amp;");
             //text = text.replace(/</g, "&lt;");
diff --git a/src/worker.js b/src/worker.js
index 0b04ceedc2277..6bee01290a6ec 100644
--- a/src/worker.js
+++ b/src/worker.js
@@ -67,8 +67,8 @@ function assert(condition, text) {
 }
 #endif
 
-function threadPrintErr() {
-  var text = Array.prototype.slice.call(arguments).join(' ');
+function threadPrintErr(...args) {
+  var text = args.join(' ');
 #if ENVIRONMENT_MAY_BE_NODE
   // See https://github.com/emscripten-core/emscripten/issues/14804
   if (ENVIRONMENT_IS_NODE) {
@@ -78,8 +78,8 @@ function threadPrintErr() {
 #endif
   console.error(text);
 }
-function threadAlert() {
-  var text = Array.prototype.slice.call(arguments).join(' ');
+function threadAlert(...args) {
+  var text = args.join(' ');
   postMessage({cmd: 'alert', text, threadId: Module['_pthread_self']()});
 }
 #if ASSERTIONS
diff --git a/test/other/metadce/test_metadce_cxx_ctors1.gzsize b/test/other/metadce/test_metadce_cxx_ctors1.gzsize
index 15f1e2d52af10..b2210331e2a74 100644
--- a/test/other/metadce/test_metadce_cxx_ctors1.gzsize
+++ b/test/other/metadce/test_metadce_cxx_ctors1.gzsize
@@ -1 +1 @@
-9950
+9962
diff --git a/test/other/metadce/test_metadce_cxx_ctors1.jssize b/test/other/metadce/test_metadce_cxx_ctors1.jssize
index 9f92ad5a75e08..f8d57866ae44d 100644
--- a/test/other/metadce/test_metadce_cxx_ctors1.jssize
+++ b/test/other/metadce/test_metadce_cxx_ctors1.jssize
@@ -1 +1 @@
-24550
+24527
diff --git a/test/other/metadce/test_metadce_cxx_ctors2.gzsize b/test/other/metadce/test_metadce_cxx_ctors2.gzsize
index 86f16586ec479..c8b3331ec48de 100644
--- a/test/other/metadce/test_metadce_cxx_ctors2.gzsize
+++ b/test/other/metadce/test_metadce_cxx_ctors2.gzsize
@@ -1 +1 @@
-9933
+9946
diff --git a/test/other/metadce/test_metadce_cxx_ctors2.jssize b/test/other/metadce/test_metadce_cxx_ctors2.jssize
index 9a0a588d1fcb0..cbac427740740 100644
--- a/test/other/metadce/test_metadce_cxx_ctors2.jssize
+++ b/test/other/metadce/test_metadce_cxx_ctors2.jssize
@@ -1 +1 @@
-24518
+24495
diff --git a/test/other/metadce/test_metadce_cxx_except.gzsize b/test/other/metadce/test_metadce_cxx_except.gzsize
index 4e2a4b06f87ef..c719006eb5801 100644
--- a/test/other/metadce/test_metadce_cxx_except.gzsize
+++ b/test/other/metadce/test_metadce_cxx_except.gzsize
@@ -1 +1 @@
-11019
+11034
diff --git a/test/other/metadce/test_metadce_cxx_except.jssize b/test/other/metadce/test_metadce_cxx_except.jssize
index 995555ed8a7c4..9cb99c368b7c2 100644
--- a/test/other/metadce/test_metadce_cxx_except.jssize
+++ b/test/other/metadce/test_metadce_cxx_except.jssize
@@ -1 +1 @@
-28439
+28417
diff --git a/test/other/metadce/test_metadce_cxx_except_wasm.gzsize b/test/other/metadce/test_metadce_cxx_except_wasm.gzsize
index a121be018ad9a..0cea14c69dd47 100644
--- a/test/other/metadce/test_metadce_cxx_except_wasm.gzsize
+++ b/test/other/metadce/test_metadce_cxx_except_wasm.gzsize
@@ -1 +1 @@
-9913
+9929
diff --git a/test/other/metadce/test_metadce_cxx_except_wasm.jssize b/test/other/metadce/test_metadce_cxx_except_wasm.jssize
index 522789f776377..670525c31d200 100644
--- a/test/other/metadce/test_metadce_cxx_except_wasm.jssize
+++ b/test/other/metadce/test_metadce_cxx_except_wasm.jssize
@@ -1 +1 @@
-24442
+24420
diff --git a/test/other/metadce/test_metadce_cxx_mangle.gzsize b/test/other/metadce/test_metadce_cxx_mangle.gzsize
index 41b390d6d2f9c..236c602c6a04b 100644
--- a/test/other/metadce/test_metadce_cxx_mangle.gzsize
+++ b/test/other/metadce/test_metadce_cxx_mangle.gzsize
@@ -1 +1 @@
-11029
+11044
diff --git a/test/other/metadce/test_metadce_cxx_mangle.jssize b/test/other/metadce/test_metadce_cxx_mangle.jssize
index 995555ed8a7c4..5a96841400c14 100644
--- a/test/other/metadce/test_metadce_cxx_mangle.jssize
+++ b/test/other/metadce/test_metadce_cxx_mangle.jssize
@@ -1 +1 @@
-28439
+28418
diff --git a/test/other/metadce/test_metadce_cxx_noexcept.gzsize b/test/other/metadce/test_metadce_cxx_noexcept.gzsize
index 15f1e2d52af10..b2210331e2a74 100644
--- a/test/other/metadce/test_metadce_cxx_noexcept.gzsize
+++ b/test/other/metadce/test_metadce_cxx_noexcept.gzsize
@@ -1 +1 @@
-9950
+9962
diff --git a/test/other/metadce/test_metadce_cxx_noexcept.jssize b/test/other/metadce/test_metadce_cxx_noexcept.jssize
index 9f92ad5a75e08..f8d57866ae44d 100644
--- a/test/other/metadce/test_metadce_cxx_noexcept.jssize
+++ b/test/other/metadce/test_metadce_cxx_noexcept.jssize
@@ -1 +1 @@
-24550
+24527
diff --git a/test/other/metadce/test_metadce_files_js_fs.gzsize b/test/other/metadce/test_metadce_files_js_fs.gzsize
index ffd7b3d6e32c8..f3d8286f8729d 100644
--- a/test/other/metadce/test_metadce_files_js_fs.gzsize
+++ b/test/other/metadce/test_metadce_files_js_fs.gzsize
@@ -1 +1 @@
-7883
+7902
diff --git a/test/other/metadce/test_metadce_files_js_fs.jssize b/test/other/metadce/test_metadce_files_js_fs.jssize
index dda2834b85a76..5552646f466d1 100644
--- a/test/other/metadce/test_metadce_files_js_fs.jssize
+++ b/test/other/metadce/test_metadce_files_js_fs.jssize
@@ -1 +1 @@
-19571
+19549
diff --git a/test/other/metadce/test_metadce_hello_O0.gzsize b/test/other/metadce/test_metadce_hello_O0.gzsize
index 853c6b04ea600..39c3a09269cd5 100644
--- a/test/other/metadce/test_metadce_hello_O0.gzsize
+++ b/test/other/metadce/test_metadce_hello_O0.gzsize
@@ -1 +1 @@
-8354
+8356
diff --git a/test/other/metadce/test_metadce_hello_O0.jssize b/test/other/metadce/test_metadce_hello_O0.jssize
index 220550f0f5811..23f8ea5cc49c9 100644
--- a/test/other/metadce/test_metadce_hello_O0.jssize
+++ b/test/other/metadce/test_metadce_hello_O0.jssize
@@ -1 +1 @@
-22939
+22921
diff --git a/test/other/metadce/test_metadce_hello_dylink.gzsize b/test/other/metadce/test_metadce_hello_dylink.gzsize
index 7f2050d840f80..c1c4623a00387 100644
--- a/test/other/metadce/test_metadce_hello_dylink.gzsize
+++ b/test/other/metadce/test_metadce_hello_dylink.gzsize
@@ -1 +1 @@
-6485
+6463
diff --git a/test/other/metadce/test_metadce_hello_dylink.jssize b/test/other/metadce/test_metadce_hello_dylink.jssize
index ad0d8dc7cb5a7..cec22ff74b489 100644
--- a/test/other/metadce/test_metadce_hello_dylink.jssize
+++ b/test/other/metadce/test_metadce_hello_dylink.jssize
@@ -1 +1 @@
-14400
+14319
diff --git a/test/other/metadce/test_metadce_minimal_O0.gzsize b/test/other/metadce/test_metadce_minimal_O0.gzsize
index 48ab8d9123e12..6d5ad234a8782 100644
--- a/test/other/metadce/test_metadce_minimal_O0.gzsize
+++ b/test/other/metadce/test_metadce_minimal_O0.gzsize
@@ -1 +1 @@
-7182
+7179
diff --git a/test/other/metadce/test_metadce_minimal_O0.jssize b/test/other/metadce/test_metadce_minimal_O0.jssize
index 5a097f8bc5725..001bc341dd32b 100644
--- a/test/other/metadce/test_metadce_minimal_O0.jssize
+++ b/test/other/metadce/test_metadce_minimal_O0.jssize
@@ -1 +1 @@
-19563
+19545
diff --git a/test/other/metadce/test_metadce_minimal_pthreads.gzsize b/test/other/metadce/test_metadce_minimal_pthreads.gzsize
index b1feb95664247..b60bc6a4327aa 100644
--- a/test/other/metadce/test_metadce_minimal_pthreads.gzsize
+++ b/test/other/metadce/test_metadce_minimal_pthreads.gzsize
@@ -1 +1 @@
-4920
+4915
diff --git a/test/other/metadce/test_metadce_minimal_pthreads.jssize b/test/other/metadce/test_metadce_minimal_pthreads.jssize
index 34e006b941803..303ec9ed755df 100644
--- a/test/other/metadce/test_metadce_minimal_pthreads.jssize
+++ b/test/other/metadce/test_metadce_minimal_pthreads.jssize
@@ -1 +1 @@
-13635
+13575
diff --git a/test/other/test_unoptimized_code_size.js.size b/test/other/test_unoptimized_code_size.js.size
index 778246d905af3..2125f43c259f1 100644
--- a/test/other/test_unoptimized_code_size.js.size
+++ b/test/other/test_unoptimized_code_size.js.size
@@ -1 +1 @@
-58187
+58173
diff --git a/test/other/test_unoptimized_code_size_strict.js.size b/test/other/test_unoptimized_code_size_strict.js.size
index 3a5f6b6493387..f01a03b1db262 100644
--- a/test/other/test_unoptimized_code_size_strict.js.size
+++ b/test/other/test_unoptimized_code_size_strict.js.size
@@ -1 +1 @@
-57079
+57065
diff --git a/test/test_other.py b/test/test_other.py
index acc284d42c1b6..6d1e37d8e46d9 100644
--- a/test/test_other.py
+++ b/test/test_other.py
@@ -6707,13 +6707,13 @@ def percent_diff(x, y):
     # main module tests
 
     # dce in main, and it fails since puts is not exported
-    test('dce', main_args=['-sMAIN_MODULE=2'], library_args=[], expected=('cannot', 'undefined'), assert_returncode=NON_ZERO)
+    test('dce', main_args=['-sMAIN_MODULE=2'], library_args=[], expected=('is not a function', 'cannot', 'undefined'), assert_returncode=NON_ZERO)
 
     # with exporting, it works
     dce = test('dce', main_args=['-sMAIN_MODULE=2', '-sEXPORTED_FUNCTIONS=_main,_puts'], library_args=[])
 
     # printf is not used in main, and we dce, so we failz
-    dce_fail = test('dce_fail', main_args=['-sMAIN_MODULE=2'], library_args=['-DUSE_PRINTF'], expected=('cannot', 'undefined'), assert_returncode=NON_ZERO)
+    dce_fail = test('dce_fail', main_args=['-sMAIN_MODULE=2'], library_args=['-DUSE_PRINTF'], expected=('is not a function', 'cannot', 'undefined'), assert_returncode=NON_ZERO)
 
     # exporting printf in main keeps it alive for the library
     test('dce_save', main_args=['-sMAIN_MODULE=2', '-sEXPORTED_FUNCTIONS=_main,_printf,_puts'], library_args=['-DUSE_PRINTF'])
@@ -13135,7 +13135,7 @@ def test_es5_transpile(self, args):
     # - logical assignment
     create_file('es6_library.js', '''\
     addToLibrary({
-      foo: function(arg="hello") {
+      foo: function(arg="hello", ...args) {
         // Object.assign + let
         let obj = Object.assign({}, {prop:1});
         err('prop: ' + obj.prop);
@@ -13178,6 +13178,8 @@ def test_es5_transpile(self, args):
         obj4 ??= 0;
         obj4 ||= 1;
         obj4 &&= 2;
+
+        console.log(...args);
       }
     });
     ''')
@@ -13197,7 +13199,7 @@ def test_es5_transpile(self, args):
     def check_for_es6(filename, expect):
       js = read_file(filename)
       if expect:
-        self.assertContained('foo(arg="hello")', js)
+        self.assertContained('foo(arg="hello"', js)
         self.assertContained(['() => 2', '()=>2'], js)
         self.assertContained('const ', js)
         self.assertContained('?.[', js)
@@ -13205,6 +13207,7 @@ def check_for_es6(filename, expect):
         self.assertContained('??=', js)
         self.assertContained('||=', js)
         self.assertContained('&&=', js)
+        self.assertContained('...', js)
       else:
         self.verify_es5(filename)
         self.assertNotContained('foo(arg=', js)
@@ -13215,6 +13218,7 @@ def check_for_es6(filename, expect):
         self.assertNotContained('?.', js)
         self.assertNotContained('||=', js)
         self.assertNotContained('&&=', js)
+        self.assertNotContained('...args', js)
 
     # Check that under normal circumstances none of these features get
     # removed / transpiled.