diff --git a/src/test/hwf.cpp b/src/test/hwf.cpp
index 69aab4c2f..be32b5400 100644
--- a/src/test/hwf.cpp
+++ b/src/test/hwf.cpp
@@ -101,7 +101,7 @@ static void bug_to_rational() {
 }
 
 static void bug_is_int() {
-    unsigned raw_val[2] = { 2147483648, 1077720461 };
+    unsigned raw_val[2] = { 2147483648u, 1077720461u };
     double   val = *(double*)(raw_val);
     std::cout << val << "\n";
     hwf_manager m;