diff --git a/.github/workflows/ubuntu-build.yml b/.github/workflows/ubuntu-build.yml
index d89f684..b45dd70 100644
--- a/.github/workflows/ubuntu-build.yml
+++ b/.github/workflows/ubuntu-build.yml
@@ -31,7 +31,8 @@ jobs:
     env:
       CC: ${{ matrix.compiler }}
       CXX: ${{ matrix.compiler == 'gcc' && 'g++' || 'clang++' }}
-      LTO_CONFIG: ${{ matrix.build_type == 'Release' && format('-DNO_STF_LTO={0} -DFULL_LTO={1}', !matrix.lto_config.lto, matrix.lto_config.full_lto) || '' }}
+      LTO_CONFIG: ${{ matrix.build_type == 'Release' && format('-DNO_STF_LTO={0}, !matrix.lto_config.lto) || '' }}
+      CLANG_FULL_LTO_CONFIG: ${{ (matrix.compiler == 'clang' && matrix.build_type == 'Release') && format('-DFULL_LTO={1}', matrix.lto_config.full_lto) || '' }}
 
     runs-on: ubuntu-latest
 
@@ -53,7 +54,7 @@ jobs:
 
     - name: Configure CMAKE
       working-directory: ${{runner.workspace}}/build
-      run: cmake $GITHUB_WORKSPACE -DCMAKE_BUILD_TYPE=${{ matrix.build_type }} -DBUILD_STF_PYTHON_LIB=ON $LTO_CONFIG
+      run: cmake $GITHUB_WORKSPACE -DCMAKE_BUILD_TYPE=${{ matrix.build_type }} -DBUILD_STF_PYTHON_LIB=ON $LTO_CONFIG $CLANG_FULL_LTO_CONFIG
 
     - name: Build
       working-directory: ${{runner.workspace}}/build