diff --git a/libavcodec/png_parser.c b/libavcodec/png_parser.c
index d07f288c4b..c66caf31a3 100644
--- a/libavcodec/png_parser.c
+++ b/libavcodec/png_parser.c
@@ -36,7 +36,7 @@ typedef struct PNGParseContext {
     ParseContext pc;
 
     int chunk_pos;          ///< position inside current chunk
-    int chunk_length;       ///< length of the current chunk
+    uint32_t chunk_length;  ///< length of the current chunk
     int remaining_size;     ///< remaining size of the current chunk
 } PNGParseContext;