diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6dd2f47..6598ac0 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -17,8 +17,7 @@ jobs:
           logger: pretty
           log-directives: nix_installer=trace
           backtrace: full
-          extra-conf: |
-            experimental-features = impure-derivations
+          extra-conf: "experimental-features = impure-derivations"
       - run: cat /etc/nix/nix.conf
       - name: echo $PATH
         run: echo $PATH