diff --git a/.gitea/workflows/check-flake.yaml b/.gitea/workflows/check-flake.yaml
index 725ad58..42ee8f6 100644
--- a/.gitea/workflows/check-flake.yaml
+++ b/.gitea/workflows/check-flake.yaml
@@ -11,7 +11,7 @@ jobs:
     container: ubuntu:latest
     steps:
       - name: Install sudo
-        run: apt-get update && apt-get install -y --no-install-recommends sudo curl
+        run: apt-get update && apt-get install -y --no-install-recommends sudo curl ca-certificates
 
       - name: Install Nix
         uses: https://github.com/cachix/install-nix-action@v20