diff --git a/lib/luks2/luks2_luks1_convert.c b/lib/luks2/luks2_luks1_convert.c
index 197170fd..3dfc19a6 100644
--- a/lib/luks2/luks2_luks1_convert.c
+++ b/lib/luks2/luks2_luks1_convert.c
@@ -215,7 +215,7 @@ static int json_luks1_segments(const struct luks_phdr *hdr_v1, struct json_objec
 
 static int json_luks1_digest(const struct luks_phdr *hdr_v1, struct json_object **digest_object)
 {
-	char keyslot_str[2], *base64_str;
+	char keyslot_str[16], *base64_str;
 	int r, ks;
 	size_t base64_len;
 	struct json_object *digest_obj, *array, *field;
diff --git a/lib/utils_loop.c b/lib/utils_loop.c
index 4bf8925e..3e9decbd 100644
--- a/lib/utils_loop.c
+++ b/lib/utils_loop.c
@@ -67,7 +67,7 @@ struct loop_config {
 
 static char *crypt_loop_get_device_old(void)
 {
-	char dev[20];
+	char dev[64];
 	int i, loop_fd;
 	struct loop_info64 lo64 = {0};