diff --git a/.github/workflows/c-cpp.yml b/.github/workflows/c-cpp.yml
index 227532a..d4d6506 100644
--- a/.github/workflows/c-cpp.yml
+++ b/.github/workflows/c-cpp.yml
@@ -13,7 +13,7 @@ jobs:
     
     strategy:
       matrix:
-        os: [ubuntu-latest, windows-latest]
+        os: [ubuntu-latest, ubuntu-20.04, windows-latest]
         build_type: [Release, Debug]
         c_compiler: [gcc, clang, cl]
         include:
@@ -42,7 +42,7 @@ jobs:
       id: strings
       shell: bash
       run: |
-        echo "build-output-dir=${{ github.workspace }}/build" >> "$GITHUB_OUTPUT"
+        echo "build-output-dir=${{ github.workspace }}/build/${{ matrix.build_type }}/${{ matrix.c_compiler }}" >> "$GITHUB_OUTPUT"
 
     - name: Configure CMake
       run: >