diff --git a/.github/workflows/cache.yaml b/.github/workflows/cache.yaml
index 14269ee..626664d 100644
--- a/.github/workflows/cache.yaml
+++ b/.github/workflows/cache.yaml
@@ -29,7 +29,7 @@ jobs:
       with:
         args: --recursive
       env:
-        AWS_S3_ENDPOINT: ${{ secrets.S3_HOST }}
+        AWS_S3_ENDPOINT: https://${{ secrets.S3_HOST }}
         AWS_S3_BUCKET: ghcup-hs
         AWS_REGION: us-west-2
         AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}