diff --git a/bin/check/check-tool.c b/bin/check/check-tool.c
index e9ab4eb633..9585054456 100644
--- a/bin/check/check-tool.c
+++ b/bin/check/check-tool.c
@@ -716,7 +716,7 @@ dump_zone(const char *zonename, dns_zone_t *zone, const char *filename,
 	FILE *output = stdout;
 	const char *flags;
 
-	flags = (fileformat == dns_masterformat_text) ? "w+" : "wb+";
+	flags = (fileformat == dns_masterformat_text) ? "w" : "wb";
 
 	if (debug) {
 		if (filename != NULL && strcmp(filename, "-") != 0)