diff --git a/coding/coding_tests/coder_util_test.cpp b/coding/coding_tests/coder_util_test.cpp
index 235f7a9bf1..cb096785e0 100644
--- a/coding/coding_tests/coder_util_test.cpp
+++ b/coding/coding_tests/coder_util_test.cpp
@@ -9,7 +9,7 @@ namespace
   size_t FixedDstSizeInfiniteMemoryEncode(char const *, size_t, char *, size_t /*dstSize*/)
   {
     // LOG(LINFO, ("DstSize", dstSize));
-    return -1;
+    return -1U;
   }
 }