diff --git a/test/layer_filtering_transport.cc b/test/layer_filtering_transport.cc
index bc9bd8977d..6bea74901d 100644
--- a/test/layer_filtering_transport.cc
+++ b/test/layer_filtering_transport.cc
@@ -125,11 +125,11 @@ bool LayerFilteringTransport::SendRtp(const uint8_t* packet,
         spatial_idx = vp9_header.spatial_idx;
         non_ref_for_inter_layer_pred = vp9_header.non_ref_for_inter_layer_pred;
         end_of_frame = vp9_header.end_of_frame;
-
-        // The number of spatial layers is sent in ssData, which is included
-        // only in the first packet of the first spatial layer of a key frame.
-        if (!vp9_header.inter_pic_predicted &&
-            vp9_header.beginning_of_frame == 1 && spatial_idx == 0) {
+        if (vp9_header.ss_data_available) {
+          RTC_DCHECK(vp9_header.temporal_idx == kNoTemporalIdx ||
+                     vp9_header.temporal_idx == 0);
+          RTC_DCHECK(vp9_header.spatial_idx == kNoSpatialIdx ||
+                     vp9_header.spatial_idx == 0);
           num_active_spatial_layers_ = vp9_header.num_spatial_layers;
         }
       }