diff --git a/test/run_all.sh b/test/run_all.sh
index b0dddbd4..b0d71e18 100755
--- a/test/run_all.sh
+++ b/test/run_all.sh
@@ -36,7 +36,7 @@ echo Running $TESTS
 for t in $TESTS; do
     echo
     greyly echo "---= Running $t =---"
-    . $t
+    (. $t)
 
     # Report test runtime when running on circle, to help scheduler
     if [ -n "$CIRCLECI" ]; then