diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e279b1c6af2..f034a2fb9a2 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -205,6 +205,8 @@ jobs:
         run: |
           echo "set(VCPKG_BUILD_TYPE release)" >> "${VCPKG_INSTALLATION_ROOT}/triplets/x64-windows.cmake"
           echo "set(VCPKG_BUILD_TYPE release)" >> "${VCPKG_INSTALLATION_ROOT}/triplets/x64-windows-static.cmake"
+          # Workaround for libevent, which requires CMake 3.1 but is incompatible with CMake >= 4.0.
+          sed -i '1s/^/set(ENV{CMAKE_POLICY_VERSION_MINIMUM} 3.5)\n/' "${VCPKG_INSTALLATION_ROOT}/scripts/ports.cmake"
 
       - name: vcpkg tools cache
         uses: actions/cache@v4