diff --git a/apps/bundle_deploy/demo_static.c b/apps/bundle_deploy/demo_static.c
index ed003738b0e6..37285351c0b8 100644
--- a/apps/bundle_deploy/demo_static.c
+++ b/apps/bundle_deploy/demo_static.c
@@ -41,12 +41,12 @@ int main(int argc, char **argv) {
   struct timeval t0, t1, t2, t3, t4, t5;
   gettimeofday(&t0, 0);
 
-  auto *handle = tvm_runtime_create(json_data, params_data, params_size);
+  void *handle = tvm_runtime_create(json_data, params_data, params_size);
   gettimeofday(&t1, 0);
 
   float input_storage[1 * 3 * 224 * 224];
   FILE * fp = fopen(argv[1], "rb");
-  fread(input_storage, 3 * 224 * 224, 4, fp);
+  (void)fread(input_storage, 3 * 224 * 224, 4, fp);
   fclose(fp);
 
   DLTensor input;
@@ -85,7 +85,7 @@ int main(int argc, char **argv) {
 
   float max_iter = -FLT_MAX;
   int32_t max_index = -1;
-  for (auto i = 0; i < OUTPUT_LEN; ++i) {
+  for (int i = 0; i < OUTPUT_LEN; ++i) {
     if (output_storage[i] > max_iter) {
       max_iter = output_storage[i];
       max_index = i;
diff --git a/src/runtime/crt/crt_backend_api.c b/src/runtime/crt/crt_backend_api.c
index 52cefafe3980..a56c15bdf01e 100644
--- a/src/runtime/crt/crt_backend_api.c
+++ b/src/runtime/crt/crt_backend_api.c
@@ -48,7 +48,7 @@ int TVMBackendParallelLaunch(FTVMParallelLambda flambda, void* cdata, int num_ta
 
 int TVMBackendRegisterSystemLibSymbol(const char* name, void* ptr) {
   g_fexecs = vrealloc(g_fexecs, sizeof(TVMPackedFunc) * (g_fexecs_count + 1));
-  snprintf(g_fexecs[g_fexecs_count].name, sizeof(g_fexecs[g_fexecs_count].name), name);
+  snprintf(g_fexecs[g_fexecs_count].name, sizeof(g_fexecs[g_fexecs_count].name), "%s", name);
   g_fexecs[g_fexecs_count].fexec = ptr;
   g_fexecs_count++;
   return 0;
diff --git a/src/runtime/crt/graph_runtime.c b/src/runtime/crt/graph_runtime.c
index b5ed3b70281b..a4c07f48ddf0 100644
--- a/src/runtime/crt/graph_runtime.c
+++ b/src/runtime/crt/graph_runtime.c
@@ -696,13 +696,13 @@ void TVMGraphRuntime_SetupStorage(TVMGraphRuntime * runtime) {
   runtime->data_entry_count = runtime->node_row_ptr[runtime->node_row_ptr_count - 1];
   runtime->data_entry = vmalloc(sizeof(TVMNDArray) * runtime->data_entry_count);
   for (idx = 0; idx < runtime->data_entry_count; ++idx) {
-    size_t storage_id = attrs->storage_id[idx];
+    uint32_t storage_id = attrs->storage_id[idx];
     CHECK(storage_id < runtime->storage_pool_count);
     runtime->data_entry[idx] =
       TVMNDArray_CreateView(&(runtime->storage_pool[storage_id]),
                          attrs->shape+idx*TVM_CRT_MAX_NDIM, attrs->ndim[idx], vtype[idx]);
     CHECK_NE(runtime->data_entry[idx].dl_tensor.data, 0,
-             "fail to create for node with idx=%d, storage_id=%lu\n", idx, storage_id);
+             "fail to create for node with idx=%d, storage_id=%u\n", idx, storage_id);
   }
 
   // Release memory
diff --git a/src/runtime/crt/load_json.c b/src/runtime/crt/load_json.c
index cf9492b8e2fa..226569ddba8a 100644
--- a/src/runtime/crt/load_json.c
+++ b/src/runtime/crt/load_json.c
@@ -182,6 +182,7 @@ int JSONReader_ReadString(JSONReader * reader, char * out_str) {
     }
     if (ch == EOF || ch == '\r' || ch == '\n') {
       fprintf(stderr, "Error at line X, Expect \'\"\' but reach end of line\n");
+      status = -1;
     }
   }
   snprintf(out_str, sizeof(output), "%s", output);
diff --git a/src/runtime/crt/ndarray.c b/src/runtime/crt/ndarray.c
index ed623fbf3de8..b0562181534e 100644
--- a/src/runtime/crt/ndarray.c
+++ b/src/runtime/crt/ndarray.c
@@ -6,9 +6,9 @@
  * to you under the Apache License, Version 2.0 (the
  * "License"); you may not use this file except in compliance
  * with the License.  You may obtain a copy of the License at
- * 
+ *
  *   http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing,
  * software distributed under the License is distributed on an
  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
@@ -92,8 +92,8 @@ int TVMNDArray_Load(TVMNDArray * ret, const char ** strm) {
   int64_t data_byte_size;
   data_byte_size = ((int64_t*)*strm)[0]; *strm += sizeof(data_byte_size);  // NOLINT(*)
   if (!(data_byte_size == num_elems * elem_bytes)) {
-    fprintf(stderr, "invalid DLTensor file format: data_byte_size=%ld, "
-            "while num_elems*elem_bytes=%ld\n",
+    fprintf(stderr, "invalid DLTensor file format: data_byte_size=%jd, "
+            "while num_elems*elem_bytes=%jd\n",
             data_byte_size, (num_elems * elem_bytes));
     status = -1;
   }