diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 54cbc20..4eed50d 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -15,6 +15,7 @@ jobs:
           - windows-latest
         ocaml-compiler:
           - 4.14.x
+          - 4.08.x
 
     runs-on: ${{ matrix.os }}