diff --git a/drivers/wdm/audio/drivers/CMIDriver/cmicontrol/main.cpp b/drivers/wdm/audio/drivers/CMIDriver/cmicontrol/main.cpp
index e5711703966..7317b363456 100644
--- a/drivers/wdm/audio/drivers/CMIDriver/cmicontrol/main.cpp
+++ b/drivers/wdm/audio/drivers/CMIDriver/cmicontrol/main.cpp
@@ -799,7 +799,7 @@ void printUsage()
 
 void deleteDriverFiles() {
 	TCHAR SysDir[MAX_PATH];
-	unsigned int len;
+	size_t len;
 	if (GetSystemDirectory(SysDir, sizeof(SysDir))==0) {
 		PrintLastError("GetSystemDirectory()");
 		return;