diff --git a/libavcodec/aac_ac3_parser.c b/libavcodec/aac_ac3_parser.c
index 2974de1545..9ab979632d 100644
--- a/libavcodec/aac_ac3_parser.c
+++ b/libavcodec/aac_ac3_parser.c
@@ -114,6 +114,10 @@ get_next:
                     buf_size -= hdr.frame_size;
                     continue;
                 }
+                /* Check for false positives since the syncword is not enough.
+                   See section 6.1.2 of A/52. */
+                if (av_crc(s->crc_ctx, 0, buf + 2, hdr.frame_size - 2))
+                    return i;
                 break;
             }
 
diff --git a/libavcodec/aac_ac3_parser.h b/libavcodec/aac_ac3_parser.h
index 560bba54f5..bc16181a19 100644
--- a/libavcodec/aac_ac3_parser.h
+++ b/libavcodec/aac_ac3_parser.h
@@ -24,6 +24,7 @@
 #define AVCODEC_AAC_AC3_PARSER_H
 
 #include <stdint.h>
+#include "libavutil/crc.h"
 #include "avcodec.h"
 #include "parser.h"
 
@@ -42,6 +43,7 @@ typedef struct AACAC3ParseContext {
     int header_size;
     int (*sync)(uint64_t state, int *need_next_header, int *new_frame_start);
 
+    const AVCRC *crc_ctx;
     int remaining_size;
     uint64_t state;
 
diff --git a/libavcodec/ac3_parser.c b/libavcodec/ac3_parser.c
index 8885e1c72e..13b8d3b7d8 100644
--- a/libavcodec/ac3_parser.c
+++ b/libavcodec/ac3_parser.c
@@ -246,6 +246,7 @@ static av_cold int ac3_parse_init(AVCodecParserContext *s1)
 {
     AACAC3ParseContext *s = s1->priv_data;
     s->header_size = AC3_HEADER_SIZE;
+    s->crc_ctx = av_crc_get_table(AV_CRC_16_ANSI);
     s->sync = ac3_sync;
     return 0;
 }