diff --git a/libavcodec/adpcm.c b/libavcodec/adpcm.c
index 9965402e585502baa7e8a8a672ddd9d3a758a89a..c86c8a72884e7a3d99c2de0e6091be2fc672e675 100644
--- a/libavcodec/adpcm.c
+++ b/libavcodec/adpcm.c
@@ -648,12 +648,9 @@ static int adpcm_decode_frame(AVCodecContext *avctx,
         }
         break;
     case CODEC_ID_ADPCM_IMA_DK4:
-        if (buf_size > BLKSIZE) {
-            if (avctx->block_align != 0)
-                buf_size = avctx->block_align;
-            else
-                buf_size = BLKSIZE;
-        }
+        if (avctx->block_align != 0 && buf_size > avctx->block_align)
+            buf_size = avctx->block_align;
+
         c->status[0].predictor = (src[0] | (src[1] << 8));
         c->status[0].step_index = src[2];
         src += 4;
@@ -687,12 +684,9 @@ static int adpcm_decode_frame(AVCodecContext *avctx,
         }
         break;
     case CODEC_ID_ADPCM_IMA_DK3:
-        if (buf_size > BLKSIZE) {
-            if (avctx->block_align != 0)
-                buf_size = avctx->block_align;
-            else
-                buf_size = BLKSIZE;
-        }
+        if (avctx->block_align != 0 && buf_size > avctx->block_align)
+            buf_size = avctx->block_align;
+
         c->status[0].predictor = (src[10] | (src[11] << 8));
         c->status[1].predictor = (src[12] | (src[13] << 8));
         c->status[0].step_index = src[14];