diff --git a/host/virtio-gpu-gfxstream-renderer.cpp b/host/virtio-gpu-gfxstream-renderer.cpp
index 7e46427..5ff4904 100644
--- a/host/virtio-gpu-gfxstream-renderer.cpp
+++ b/host/virtio-gpu-gfxstream-renderer.cpp
@@ -2502,6 +2502,8 @@
     GFXSTREAM_SET_FEATURE_ON_CONDITION(
         &features, ExternalBlob,
         renderer_flags & STREAM_RENDERER_FLAGS_USE_EXTERNAL_BLOB);
+    GFXSTREAM_SET_FEATURE_ON_CONDITION(&features, VulkanExternalSync,
+                                       renderer_flags & STREAM_RENDERER_FLAGS_VULKAN_EXTERNAL_SYNC);
     GFXSTREAM_SET_FEATURE_ON_CONDITION(
         &features, GlAsyncSwap, false);
     GFXSTREAM_SET_FEATURE_ON_CONDITION(
@@ -2779,6 +2781,10 @@
         return -EINVAL;
     }
 
+#if GFXSTREAM_UNSTABLE_VULKAN_EXTERNAL_SYNC
+    renderer_flags |= STREAM_RENDERER_FLAGS_VULKAN_EXTERNAL_SYNC;
+#endif
+
     gfxstream::host::FeatureSet features;
     int ret = parseGfxstreamFeatures(renderer_flags, renderer_features_str, features);
     if (ret) {