diff --git a/src/makefile.c b/src/makefile.c
index fd8235e..01e28a5 100644
--- a/src/makefile.c
+++ b/src/makefile.c
@@ -2650,7 +2650,7 @@ static int _makefile_print(FILE * fp, char const * format, ...)
 
 	va_start(ap, format);
 	if(fp == NULL)
-		ret = vsprintf(NULL, format, ap);
+		ret = vsnprintf(NULL, 0, format, ap);
 	else
 		ret = vfprintf(fp, format, ap);
 	va_end(ap);