diff --git a/src/core/ext/transport/chttp2/transport/internal.h b/src/core/ext/transport/chttp2/transport/internal.h
index be905e7f485..9e3337536e9 100644
--- a/src/core/ext/transport/chttp2/transport/internal.h
+++ b/src/core/ext/transport/chttp2/transport/internal.h
@@ -511,7 +511,7 @@ struct grpc_chttp2_stream {
   // stream->pending_byte_stream == true. The value is saved before
   // application threads are allowed to modify
   // unprocessed_incoming_frames_buffer
-  int32_t unprocessed_incoming_frames_buffer_cached_length;
+  size_t unprocessed_incoming_frames_buffer_cached_length;
   grpc_closure reset_byte_stream;
   grpc_error* byte_stream_error; /* protected by t combiner */
   bool received_last_frame;      /* protected by t combiner */