diff --git a/src/xrCore/_math.cpp b/src/xrCore/_math.cpp
index 5fcd78abc45..d7fafbe4d7c 100644
--- a/src/xrCore/_math.cpp
+++ b/src/xrCore/_math.cpp
@@ -199,7 +199,7 @@ void Detect()
     // Detect QPC Overhead
     QueryPerformanceFrequency((PLARGE_INTEGER)&qpc_freq);
     qpc_overhead = 0;
-    for (i = 0; i < 256; i++)
+    for (int i = 0; i < 256; i++)
     {
         start = QPC();
         qpc_overhead += QPC() - start - dummy;