diff --git a/src/tools/pkcs15-tool.c b/src/tools/pkcs15-tool.c
index 3544b5ed..bbf6e7d6 100644
--- a/src/tools/pkcs15-tool.c
+++ b/src/tools/pkcs15-tool.c
@@ -145,7 +145,7 @@ static struct sc_pkcs15_card *p15card = NULL;
 
 struct _access_rule_text {
 	unsigned flag;
-	char *label;
+	const char *label;
 } _access_rules_text[] = {
 	{SC_PKCS15_ACCESS_RULE_MODE_READ, "read"},
 	{SC_PKCS15_ACCESS_RULE_MODE_UPDATE, "update"},