diff --git a/advice.c b/advice.c
index 65a07859f2..961a4f5e41 100644
--- a/advice.c
+++ b/advice.c
@@ -26,7 +26,7 @@ void advise(const char *advice, ...)
 	const char *cp, *np;
 
 	va_start(params, advice);
-	strbuf_addf(&buf, advice, params);
+	strbuf_vaddf(&buf, advice, params);
 	va_end(params);
 
 	for (cp = buf.buf; *cp; cp = np) {