diff --git a/scripts/check-script-contract.test.sh b/scripts/check-script-contract.test.sh
index 96d415882ab..ee64c83ff49 100755
--- a/scripts/check-script-contract.test.sh
+++ b/scripts/check-script-contract.test.sh
@@ -39,6 +39,9 @@
 # basename is also what routes a member's changes back here, since
 # scripts/affected-tests.sh selects any suite that NAMES the changed file.
 set -uo pipefail
+# Members read CHECK_DATA_ROOT in place of the tree they are run in, so a
+# caller's value would point every fixture run at that caller's tree.
+unset CHECK_DATA_ROOT
 
 SELF_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)" || exit 2
 REPO_ROOT="$(cd "$SELF_DIR/.." && pwd)" || exit 2