diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index dd4c1a5..2030968 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -23,6 +23,7 @@ jobs:
       with:
         coverage: xdebug
         php-version: 5.5
+        extensions: crypto
         ini-values: xdebug.overload_var_dump=0, memory_limit=4G, phar.readonly=false
 
     - name: Checkout