diff --git a/core/membuffer.c b/core/membuffer.c
index aa08bb5ea..18a0203fc 100644
--- a/core/membuffer.c
+++ b/core/membuffer.c
@@ -213,7 +213,7 @@ void put_quoted(struct membuffer *b, const char *text, int is_attribute, int is_
 {
 	const char *p = text;
 
-	for (;;) {
+	for (;text;) {
 		const char *escape;
 
 		switch (*p++) {