diff --git a/libavcodec/avpacket.c b/libavcodec/avpacket.c
index 8e028a2a6c..60269aa63d 100644
--- a/libavcodec/avpacket.c
+++ b/libavcodec/avpacket.c
@@ -508,7 +508,7 @@ int av_packet_unpack_dictionary(const uint8_t *data, int size, AVDictionary **di
         const uint8_t *key = data;
         const uint8_t *val = data + strlen(key) + 1;
 
-        if (val >= end)
+        if (val >= end || !*key)
             return AVERROR_INVALIDDATA;
 
         ret = av_dict_set(dict, key, val, 0);