diff --git a/test/decode_api_test.cc b/test/decode_api_test.cc
index 06790645f86b3699127ab705f72175a4879f663a..72fdfc7bc60e0497dc155423e087da1667da3e4f 100644
--- a/test/decode_api_test.cc
+++ b/test/decode_api_test.cc
@@ -81,6 +81,24 @@ void TestVp9Controls(vpx_codec_ctx_t *dec) {
     EXPECT_EQ(VPX_CODEC_INVALID_PARAM,
               vpx_codec_control_(dec, kControls[i], NULL));
   }
+
+  vp9_ref_frame_t ref;
+  ref.idx = 0;
+  EXPECT_EQ(VPX_CODEC_ERROR, vpx_codec_control(dec, VP9_GET_REFERENCE, &ref));
+  EXPECT_EQ(VPX_CODEC_INVALID_PARAM,
+            vpx_codec_control(dec, VP9_GET_REFERENCE, NULL));
+
+  vpx_ref_frame_t ref_copy;
+  const int width = 352;
+  const int height = 288;
+  ASSERT_TRUE(
+      vpx_img_alloc(&ref_copy.img, VPX_IMG_FMT_I420, width, height, 1) != NULL);
+  ref_copy.frame_type = VP8_LAST_FRAME;
+  EXPECT_EQ(VPX_CODEC_ERROR,
+            vpx_codec_control(dec, VP8_COPY_REFERENCE, &ref_copy));
+  EXPECT_EQ(VPX_CODEC_INVALID_PARAM,
+            vpx_codec_control(dec, VP8_COPY_REFERENCE, NULL));
+  vpx_img_free(&ref_copy.img);
 }
 
 TEST(DecodeAPI, Vp9InvalidDecode) {
diff --git a/vp9/common/vp9_onyxc_int.h b/vp9/common/vp9_onyxc_int.h
index ae32aff7de394baba19770f9766dfbf5815f7e45..dff077c112c0111051091510501a45dcd1eed0d0 100644
--- a/vp9/common/vp9_onyxc_int.h
+++ b/vp9/common/vp9_onyxc_int.h
@@ -205,6 +205,9 @@ typedef struct VP9Common {
 static INLINE YV12_BUFFER_CONFIG *get_ref_frame(VP9_COMMON *cm, int index) {
   if (index < 0 || index >= REF_FRAMES)
     return NULL;
+  if (cm->ref_frame_map[index] < 0)
+    return NULL;
+  assert(cm->ref_frame_map[index] < REF_FRAMES);
   return &cm->frame_bufs[cm->ref_frame_map[index]].buf;
 }