diff --git a/libavcodec/j2kdec.c b/libavcodec/j2kdec.c
index c4cf017129..6989aa1cd7 100644
--- a/libavcodec/j2kdec.c
+++ b/libavcodec/j2kdec.c
@@ -921,7 +921,7 @@ static int decode_codestream(J2kDecoderContext *s)
 
         marker = bytestream_get_be16(&s->buf);
         if(s->avctx->debug & FF_DEBUG_STARTCODE)
-            av_log(s->avctx, AV_LOG_DEBUG, "marker 0x%.4X at pos 0x%x\n", marker, s->buf - s->buf_start - 4);
+            av_log(s->avctx, AV_LOG_DEBUG, "marker 0x%.4X at pos 0x%tx\n", marker, s->buf - s->buf_start - 4);
         oldbuf = s->buf;
 
         if (marker == J2K_SOD){