diff --git a/libavcodec/ac3.h b/libavcodec/ac3.h
index f8f6a81f45..e358f8d9e3 100644
--- a/libavcodec/ac3.h
+++ b/libavcodec/ac3.h
@@ -27,7 +27,6 @@
 #ifndef AVCODEC_AC3_H
 #define AVCODEC_AC3_H
 
-#define AC3_MAX_CODED_FRAME_SIZE 3840 /* in bytes */
 #define EAC3_MAX_CHANNELS 16          /**< maximum number of channels in EAC3 */
 #define AC3_MAX_CHANNELS 7            /**< maximum number of channels, including coupling channel */
 #define CPL_CH 0                      /**< coupling channel index */
diff --git a/libavcodec/ac3enc.c b/libavcodec/ac3enc.c
index 8044e6dcd0..4cfd0afe12 100644
--- a/libavcodec/ac3enc.c
+++ b/libavcodec/ac3enc.c
@@ -1729,7 +1729,7 @@ static void ac3_output_frame(AC3EncodeContext *s, unsigned char *frame)
 {
     int blk;
 
-    init_put_bits(&s->pb, frame, AC3_MAX_CODED_FRAME_SIZE);
+    init_put_bits(&s->pb, frame, s->frame_size);
 
     s->output_frame_header(s);