diff --git a/t/lib-git-p4.sh b/t/lib-git-p4.sh
index 2098b9ba05..ccd918e79e 100644
--- a/t/lib-git-p4.sh
+++ b/t/lib-git-p4.sh
@@ -48,7 +48,8 @@ P4DPORT=$((10669 + ($testid - $git_p4_test_start)))
 P4PORT=localhost:$P4DPORT
 P4CLIENT=client
 P4EDITOR=:
-export P4PORT P4CLIENT P4EDITOR
+unset P4CHARSET
+export P4PORT P4CLIENT P4EDITOR P4CHARSET
 
 db="$TRASH_DIRECTORY/db"
 cli="$TRASH_DIRECTORY/cli"