diff --git a/modules/video_coding/utility/ivf_file_reader.cc b/modules/video_coding/utility/ivf_file_reader.cc
index e3c249947d..f326c8cb53 100644
--- a/modules/video_coding/utility/ivf_file_reader.cc
+++ b/modules/video_coding/utility/ivf_file_reader.cc
@@ -164,7 +164,7 @@ absl::optional<EncodedImage> IvfFileReader::NextFrame() {
     image.SetTimestamp(static_cast<uint32_t>(current_timestamp));
   }
   image.SetEncodedData(payload);
-  image.SetSpatialIndex(static_cast<int>(layer_sizes.size()));
+  image.SetSpatialIndex(static_cast<int>(layer_sizes.size()) - 1);
   for (size_t i = 0; i < layer_sizes.size(); ++i) {
     image.SetSpatialLayerFrameSize(static_cast<int>(i), layer_sizes[i]);
   }
diff --git a/modules/video_coding/utility/ivf_file_reader_unittest.cc b/modules/video_coding/utility/ivf_file_reader_unittest.cc
index 58a808840d..c9cf14674b 100644
--- a/modules/video_coding/utility/ivf_file_reader_unittest.cc
+++ b/modules/video_coding/utility/ivf_file_reader_unittest.cc
@@ -83,7 +83,7 @@ class IvfFileReaderTest : public ::testing::Test {
                      bool use_capture_tims_ms,
                      int spatial_layers_count) {
     ASSERT_TRUE(frame);
-    EXPECT_EQ(frame->SpatialIndex(), spatial_layers_count);
+    EXPECT_EQ(frame->SpatialIndex(), spatial_layers_count - 1);
     if (use_capture_tims_ms) {
       EXPECT_EQ(frame->capture_time_ms_, static_cast<int64_t>(frame_index));
       EXPECT_EQ(frame->Timestamp(), static_cast<int64_t>(90 * frame_index));