diff --git a/videodecoder/VideoDecoderAVC.cpp b/videodecoder/VideoDecoderAVC.cpp
index a415a20..27c1e1d 100644
--- a/videodecoder/VideoDecoderAVC.cpp
+++ b/videodecoder/VideoDecoderAVC.cpp
@@ -388,7 +388,7 @@
     picParam->CurrPic.picture_id = mAcquiredBuffer->renderBuffer.surface;
 
     // build new DPB
-    for (int32_t i = 0; i < DPB_SIZE; i++, ref++) {
+    for (int32_t i = 0; i < MAX_REF_NUMBER; i++, ref++) {
         if (ref->flags & VA_PICTURE_H264_INVALID) {
             continue;
         }
diff --git a/videodecoder/VideoDecoderAVC.h b/videodecoder/VideoDecoderAVC.h
index 2d8d1b6..c3a1fe5 100644
--- a/videodecoder/VideoDecoderAVC.h
+++ b/videodecoder/VideoDecoderAVC.h
@@ -67,7 +67,8 @@
     enum {
         AVC_EXTRA_SURFACE_NUMBER = 6,
         // maximum DPB (Decoded Picture Buffer) size
-        DPB_SIZE = 16,
+        MAX_REF_NUMBER = 16,
+        DPB_SIZE = 17,         // DPB_SIZE = MAX_REF_NUMBER + 1,
         REF_LIST_SIZE = 32,
     };