diff --git a/dlls/winemp3.acm/mpg123.h b/dlls/winemp3.acm/mpg123.h
index 23f1a66c1b6..b397641a09c 100644
--- a/dlls/winemp3.acm/mpg123.h
+++ b/dlls/winemp3.acm/mpg123.h
@@ -61,7 +61,7 @@
 #ifndef FALSE
 #define         FALSE                   0
 #endif
-#ifndef FALSE
+#ifndef TRUE
 #define         TRUE                    1
 #endif