diff --git a/.gitea/workflows/build.yml b/.gitea/workflows/build.yml
index cbb1b2092..f5d34b989 100644
--- a/.gitea/workflows/build.yml
+++ b/.gitea/workflows/build.yml
@@ -71,7 +71,11 @@ jobs:
       - name: Install vcpkg native deps
         shell: powershell
         run: |
-          C:\vcpkg\vcpkg.exe install --triplet x64-windows-static libvpx libyuv opus aom libjpeg-turbo
+          # --feature-flags=-manifests forces classic mode -- the repo
+          # has a vcpkg.json that pulls in ffmpeg+amf+nvcodec+qsv (hwcodec
+          # path) which is a 2hr build and not needed for Sciter UI.
+          # Sciter only needs the codec/image libs below.
+          C:\vcpkg\vcpkg.exe install --feature-flags=-manifests --triplet x64-windows-static libvpx libyuv opus aom libjpeg-turbo
 
       - name: cargo build --release (Sciter UI)
         shell: powershell