diff --git a/test/core/slice/b64_decode_fuzzer.cc b/test/core/slice/b64_decode_fuzzer.cc
index 0ef50895f95..96ca91af1b8 100644
--- a/test/core/slice/b64_decode_fuzzer.cc
+++ b/test/core/slice/b64_decode_fuzzer.cc
@@ -27,7 +27,8 @@ bool leak_check = true;
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
   if (size < 1) return 0;
   const bool url_safe = static_cast<uint8_t>(0x100) < data[0];
-  grpc_base64_decode_with_len(reinterpret_cast<const char*>(data + 1), size - 1,
-                              url_safe);
+  grpc_slice res = grpc_base64_decode_with_len(
+      reinterpret_cast<const char*>(data + 1), size - 1, url_safe);
+  grpc_slice_unref(res);
   return 0;
 }