diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index c67e1e0..5b79d8c 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -70,6 +70,9 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-composer-
 
+      - name: Keep composer v1 until all dev dependencies are v2 ready
+        run: sudo composer selfupdate --1
+
       - name: Install dependencies
         run: composer install --prefer-dist --no-progress --no-suggest --no-plugins
 
@@ -139,6 +142,9 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-composer-
 
+      - name: Keep composer v1 until all dev dependencies are v2 ready
+        run: sudo composer selfupdate --1
+
       - name: Install dependencies
         run: composer install --prefer-dist --no-progress --no-suggest