diff --git a/tests/functional/flakes/develop.sh b/tests/functional/flakes/develop.sh
index b3e438e99..c222f0fbb 100755
--- a/tests/functional/flakes/develop.sh
+++ b/tests/functional/flakes/develop.sh
@@ -122,7 +122,7 @@ expectStderr 1 nix develop --unset-env-var FOO --set-env-var FOO 'BAR' --no-writ
   grepQuiet "error: Cannot set environment variable 'FOO' that is unset with '--unset-env-var'"
 
 # Check that multiple `--ignore-env`'s are okay.
-expectStderr 0 nix develop --ignore-env --set-env-var FOO 'BAR' --ignore-env .#hello
+expectStderr 0 nix develop --ignore-env --set-env-var FOO 'BAR' --ignore-env .#hello < /dev/null
 
 # Determine the bashInteractive executable.
 nix build --no-write-lock-file './nixpkgs#bashInteractive' --out-link ./bash-interactive