diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index be9d8421..a722760e 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -92,7 +92,7 @@ jobs:
 
     - name: Install VapourSynth
       run: |
-        git clone https://github.com/vapoursynth/vapoursynth --depth 1 vapoursynth-build
+        git clone https://github.com/vapoursynth/vapoursynth --branch api3 --depth 1 vapoursynth-build
         pushd vapoursynth-build
         ./autogen.sh
         ./configure --disable-static --disable-x86-asm --disable-vsscript --disable-vspipe --disable-python-module --disable-plugins