diff --git a/.github/workflows/haskell-ci.yml b/.github/workflows/haskell-ci.yml
index 07497bfc..4be34f2b 100644
--- a/.github/workflows/haskell-ci.yml
+++ b/.github/workflows/haskell-ci.yml
@@ -142,7 +142,8 @@ jobs:
             branch:   master
 
           package xmonad-contrib
-            flags: +pedantic
+            flags:       +pedantic
+            ghc-options: -j
           EOF
           $HCPKG list --simple-output --names-only | perl -ne 'for (split /\s+/) { print "constraints: $_ installed\n" unless /^(xmonad-contrib)$/; }' >> cabal.project.local
           cat cabal.project
diff --git a/cabal.haskell-ci b/cabal.haskell-ci
index 0b0762d8..2b900c6c 100644
--- a/cabal.haskell-ci
+++ b/cabal.haskell-ci
@@ -9,3 +9,4 @@ apt:
 raw-project
   package xmonad-contrib
     flags: +pedantic
+    ghc-options: -j
diff --git a/stack-master.yaml b/stack-master.yaml
index 31992976..ea07bf81 100644
--- a/stack-master.yaml
+++ b/stack-master.yaml
@@ -9,3 +9,6 @@ packages:
 extra-deps:
 - github: xmonad/xmonad
   commit: master@{today}
+
+ghc-options:
+  xmonad-contrib: '-j'
diff --git a/stack.yaml b/stack.yaml
index 14bc9e00..d6e3356e 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -15,3 +15,6 @@ nix:
     - xorg.libXrandr
     - xorg.libXrender
     - xorg.libXScrnSaver
+
+ghc-options:
+  xmonad-contrib: '-j'