diff --git a/libavformat/hls_sample_encryption.c b/libavformat/hls_sample_encryption.c
index f9f410f3da..26de098dda 100644
--- a/libavformat/hls_sample_encryption.c
+++ b/libavformat/hls_sample_encryption.c
@@ -88,6 +88,7 @@ void ff_hls_senc_read_audio_setup_info(HLSAudioSetupInfo *info, const uint8_t *b
         return;
 
     memcpy(info->setup_data, buf, info->setup_data_length);
+    memset(info->setup_data + info->setup_data_length, 0, AV_INPUT_BUFFER_PADDING_SIZE);
 }
 
 int ff_hls_senc_parse_audio_setup_info(AVStream *st, HLSAudioSetupInfo *info)
diff --git a/libavformat/hls_sample_encryption.h b/libavformat/hls_sample_encryption.h
index e5a2eae01d..0f7e1c3ece 100644
--- a/libavformat/hls_sample_encryption.h
+++ b/libavformat/hls_sample_encryption.h
@@ -52,7 +52,7 @@ typedef struct HLSAudioSetupInfo {
     uint16_t            priming;
     uint8_t             version;
     uint8_t             setup_data_length;
-    uint8_t             setup_data[HLS_MAX_AUDIO_SETUP_DATA_LEN];
+    uint8_t             setup_data[HLS_MAX_AUDIO_SETUP_DATA_LEN + AV_INPUT_BUFFER_PADDING_SIZE];
 } HLSAudioSetupInfo;