diff --git a/.github/workflows/test-build-system.yml b/.github/workflows/test-build-system.yml
index 9320001..16a0def 100644
--- a/.github/workflows/test-build-system.yml
+++ b/.github/workflows/test-build-system.yml
@@ -30,7 +30,7 @@ jobs:
     - name: Check GTK 4 UI generation works
       run: |
         echo "echo \$@" | sudo tee /usr/bin/gtk-builder-tool; sudo chmod +x /usr/bin/gtk-builder-tool
-        make gtk4
+        make gtk4 "-j$(nproc)"
 
     - name: Test extension builds from current state
       run: |