diff --git a/test-hg.sh b/test-hg.sh
index 72f745d..fa7d17b 100755
--- a/test-hg.sh
+++ b/test-hg.sh
@@ -8,7 +8,8 @@
 
 test_description='Test remote-hg'
 
-. ./test-lib.sh
+test -n "$TEST_DIRECTORY" || TEST_DIRECTORY=${0%/*}/../../t
+. "$TEST_DIRECTORY"/test-lib.sh
 
 if ! test_have_prereq PYTHON
 then