diff --git a/tests/test-subrepo-git.t b/tests/test-subrepo-git.t
--- a/tests/test-subrepo-git.t
+++ b/tests/test-subrepo-git.t
@@ -10,6 +10,7 @@ make git commits repeatable
   $ GIT_COMMITTER_NAME="$GIT_AUTHOR_NAME"; export GIT_COMMITTER_NAME
   $ GIT_COMMITTER_EMAIL="$GIT_AUTHOR_EMAIL"; export GIT_COMMITTER_EMAIL
   $ GIT_COMMITTER_DATE="$GIT_AUTHOR_DATE"; export GIT_COMMITTER_DATE
+  $ GIT_CONFIG_NOSYSTEM=1; export GIT_CONFIG_NOSYSTEM
 
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