diff --git a/fuzz/fuzzers/roundtrip_no_pad.rs b/fuzz/fuzzers/roundtrip_no_pad.rs
index 23cff9e..813fcf6 100644
--- a/fuzz/fuzzers/roundtrip_no_pad.rs
+++ b/fuzz/fuzzers/roundtrip_no_pad.rs
@@ -1,11 +1,14 @@
 #![no_main]
-#[macro_use] extern crate libfuzzer_sys;
+#[macro_use]
+extern crate libfuzzer_sys;
 extern crate base64;
 
 use base64::engine::fast_portable;
 
 fuzz_target!(|data: &[u8]| {
-    let config = fast_portable::FastPortableConfig::new().with_encode_padding(false);
+    let config = fast_portable::FastPortableConfig::new()
+        .with_encode_padding(false)
+        .with_decode_padding_mode(fast_portable::DecodePaddingMode::RequireNone);
     let engine = fast_portable::FastPortable::from(&base64::alphabet::STANDARD, config);
 
     let encoded = base64::encode_engine(&data, &engine);
diff --git a/fuzz/fuzzers/utils.rs b/fuzz/fuzzers/utils.rs
index c1d7edf..0e7e190 100644
--- a/fuzz/fuzzers/utils.rs
+++ b/fuzz/fuzzers/utils.rs
@@ -22,9 +22,16 @@ pub fn random_engine(data: &[u8]) -> fast_portable::FastPortable {
         alphabet::STANDARD
     };
 
+    let encode_padding = rng.gen();
+    let decode_padding = if encode_padding {
+        fast_portable::DecodePaddingMode::RequireCanonical
+    } else {
+        fast_portable::DecodePaddingMode::RequireNone
+    };
     let config = fast_portable::FastPortableConfig::new()
-        .with_encode_padding(rng.gen())
-        .with_decode_allow_trailing_bits(rng.gen());
+        .with_encode_padding(encode_padding)
+        .with_decode_allow_trailing_bits(rng.gen())
+        .with_decode_padding_mode(decode_padding);
 
     fast_portable::FastPortable::from(&alphabet, config)
 }