diff --git a/tests/functional/ca/duplicate-realisation-in-closure.sh b/tests/functional/ca/duplicate-realisation-in-closure.sh
index da9cd8fb4..0baf15cc2 100644
--- a/tests/functional/ca/duplicate-realisation-in-closure.sh
+++ b/tests/functional/ca/duplicate-realisation-in-closure.sh
@@ -1,3 +1,5 @@
+#!/usr/bin/env bash
+
 source ./common.sh
 
 requireDaemonNewerThan "2.4pre20210625"
@@ -5,7 +7,7 @@ requireDaemonNewerThan "2.4pre20210625"
 export REMOTE_STORE_DIR="$TEST_ROOT/remote_store"
 export REMOTE_STORE="file://$REMOTE_STORE_DIR"
 
-rm -rf $REMOTE_STORE_DIR
+rm -rf "$REMOTE_STORE_DIR"
 clearStore
 
 # Build dep1 and push that to the binary cache.