diff --git a/src/screen.h b/src/screen.h
index ff53a01..c59ca8a 100644
--- a/src/screen.h
+++ b/src/screen.h
@@ -48,7 +48,7 @@
 # define debug(format, ...) {if(dfp){fprintf(dfp, format, ##__VA_ARGS__);}}
   extern FILE *dfp;
 #else
-# define debug(format, ...)
+# define debug(format, ...) {}
 #endif
 
 #ifndef DEBUG