diff --git a/lib/test-hexdump.c b/lib/test-hexdump.c
index 9846ff7..c227cc4 100644
--- a/lib/test-hexdump.c
+++ b/lib/test-hexdump.c
@@ -48,7 +48,7 @@
 	char test[32 * 3 + 2 + 32 + 1];
 	char real[32 * 3 + 2 + 32 + 1];
 	char *p;
-	const char **result;
+	const char * const *result;
 	size_t l = len;
 	int gs = groupsize, rs = rowsize;
 	unsigned int i;