diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index a32b9ba..ae8220f 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -15,7 +15,7 @@ env:
 # for matrix check https://docs.github.com/en/actions/reference/specifications-for-github-hosted-runners
 jobs:
   prepare_matrix:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-slim
     outputs:
       matrix: ${{ steps.matrix_setup.outputs.matrix }}
     steps:
diff --git a/conanfile.py b/conanfile.py
index 4660a76..bc59d6c 100644
--- a/conanfile.py
+++ b/conanfile.py
@@ -100,7 +100,7 @@ def generate(self):
         tc.variables["ManiVault_DIR"] = manivault_dir
 
         # Set some build options
-        tc.variables["MV_UNITY_BUILD"] = "ON"
+        tc.cache_variables["MV_UNITY_BUILD"] = "ON"
 
         # Use vcpkg-installed dependencies if there are any
         if os.environ.get("VCPKG_ROOT", None):