diff --git a/.github/workflows/PR.yml b/.github/workflows/PR.yml
index 8a87a6e20..e6818865f 100644
--- a/.github/workflows/PR.yml
+++ b/.github/workflows/PR.yml
@@ -26,6 +26,10 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v3
 
+
+      - name: Install dev version of GT
+        run: opam source GT --dev-repo
+
       - name: Install dependencies for documentation
         run: opam install odoc pa_ppx --yes
 
diff --git a/.github/workflows/master.yml b/.github/workflows/master.yml
index c9583d904..a2d9ef8f6 100644
--- a/.github/workflows/master.yml
+++ b/.github/workflows/master.yml
@@ -37,6 +37,12 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v3
 
+      - run: opam update
+      - name: Install dev version of GT
+        run: |
+          opam source GT --dev-repo
+          opam pin add GT ./GT -y
+
       - name: Install dependencies for documentation
         run: opam install odoc pa_ppx --yes