diff --git a/libavcodec/adx.h b/libavcodec/adx.h
index 8d5e0869ae..60ce07ad61 100644
--- a/libavcodec/adx.h
+++ b/libavcodec/adx.h
@@ -35,9 +35,11 @@ typedef struct ADXChannelState {
     int s1,s2;
 } ADXChannelState;
 
+#define MAX_CHANNELS 6
+
 typedef struct ADXContext {
     int channels;
-    ADXChannelState prev[2];
+    ADXChannelState prev[MAX_CHANNELS];
     int header_parsed;
     int eof;
     int cutoff;
diff --git a/libavcodec/adxdec.c b/libavcodec/adxdec.c
index 97a7e59686..4300dede5e 100644
--- a/libavcodec/adxdec.c
+++ b/libavcodec/adxdec.c
@@ -70,7 +70,7 @@ static int adx_decode_header(AVCodecContext *avctx, const uint8_t *buf,
 
     /* channels */
     channels = buf[7];
-    if (channels <= 0 || channels > 2)
+    if (channels <= 0 || channels > MAX_CHANNELS)
         return AVERROR_INVALIDDATA;
 
     if (avctx->ch_layout.nb_channels != channels) {