--- a/js/src/wasm/WasmValidate.cpp
+++ b/js/src/wasm/WasmValidate.cpp
@@ -613,18 +613,18 @@ DecodePreamble(Decoder& d)
     if (d.bytesRemain() > MaxModuleBytes)
         return d.fail("module too big");
 
     uint32_t u32;
     if (!d.readFixedU32(&u32) || u32 != MagicNumber)
         return d.fail("failed to match magic number");
 
     if (!d.readFixedU32(&u32) || u32 != EncodingVersion) {
-        return d.fail("binary version 0x%" PRIx32 " does not match expected version 0x%" PRIx32,
-                      u32, EncodingVersion);
+        return d.failf("binary version 0x%" PRIx32 " does not match expected version 0x%" PRIx32,
+                       u32, EncodingVersion);
     }
 
     return true;
 }
 
 static bool
 DecodeTypeSection(Decoder& d, ModuleEnvironment* env)
 {