diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index fc74a490..bf750ac5 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -9,7 +9,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, macOS-latest]
-        stack: ["2.7.3"]
+        stack: ["2.15.7"]
 
     steps:
     - name: Get the version