THRIFT-4515: fix windows build
Client: cpp
diff --git a/lib/cpp/test/concurrency/Tests.cpp b/lib/cpp/test/concurrency/Tests.cpp
index df5099d..fc0ba7f 100644
--- a/lib/cpp/test/concurrency/Tests.cpp
+++ b/lib/cpp/test/concurrency/Tests.cpp
@@ -27,7 +27,7 @@
 
 // The test weight, where 10 is 10 times more threads than baseline
 // and the baseline is optimized for running in valgrind
-static size_t WEIGHT = 10;
+static int WEIGHT = 10;
 
 int main(int argc, char** argv) {