diff --git a/tools/trace-malloc/lib/nsTraceMalloc.h b/tools/trace-malloc/lib/nsTraceMalloc.h
index 9d821a32903..b2e5bbef384 100644
--- a/tools/trace-malloc/lib/nsTraceMalloc.h
+++ b/tools/trace-malloc/lib/nsTraceMalloc.h
@@ -43,8 +43,8 @@
 #include <stdio.h> /* for FILE */
 #include "prtypes.h"
 
-#ifdef XP_WIN
-#define setlinebuf(stream) setvbuf((stream), (char *)NULL, _IOLBF, 0)
+#ifdef XP_WIN
+#define setlinebuf(stream) setvbuf((stream), (char *)NULL, _IOLBF, 0)
 #endif
 
 PR_BEGIN_EXTERN_C