diff --git a/lib/dns/master.c b/lib/dns/master.c
index 36f6305293..fc561076c5 100644
--- a/lib/dns/master.c
+++ b/lib/dns/master.c
@@ -1101,7 +1101,7 @@ load_text(dns_loadctx_t *lctx) {
 	char *lhs = NULL;
 	char *gtype = NULL;
 	char *rhs = NULL;
-	const char *source = "";
+	const char *source;
 	unsigned long line = 0;
 	bool explicit_ttl;
 	char classname1[DNS_RDATACLASS_FORMATSIZE];