diff --git a/t/test-lib.sh b/t/test-lib.sh
index 9e2b711..2ac9536 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -61,6 +61,7 @@
 	my @vars = grep(/^GIT_/ && !/^GIT_($ok)/o, @env);
 	print join("\n", @vars);
 ')
+unset XDG_CONFIG_HOME
 GIT_AUTHOR_EMAIL=author@example.com
 GIT_AUTHOR_NAME='A U Thor'
 GIT_COMMITTER_EMAIL=committer@example.com