diff --git a/ltdl_win.c b/ltdl_win.c
index 0027cbd..bd5ec3e 100644
--- a/ltdl_win.c
+++ b/ltdl_win.c
@@ -52,7 +52,7 @@ void win32_mapSo2Dll( char *path )
     }
     //.so -> .dll
     if (len>3 && strncmp(path+len-3,".so",3)==0) {
-#ifndef QT_NO_DEBUG //debug library version
+#ifndef TQT_NO_DEBUG //debug library version
         strcpy(path+len-3, "_d");
         len += 2;
 #endif