diff --git a/test/core/transport/chttp2/flow_control_fuzzer.cc b/test/core/transport/chttp2/flow_control_fuzzer.cc
index 43f92fc7e45..013577b407f 100644
--- a/test/core/transport/chttp2/flow_control_fuzzer.cc
+++ b/test/core/transport/chttp2/flow_control_fuzzer.cc
@@ -377,7 +377,7 @@ void FlowControlFuzzer::AssertNoneStuck() const {
 }
 
 void FlowControlFuzzer::AssertAnnouncedOverInitialWindowSizeCorrect() const {
-  uint64_t value_from_streams = 0;
+  int64_t value_from_streams = 0;
 
   for (const auto& id_stream : streams_) {
     const auto& stream = id_stream.second;