test_expect_success \
        'encode(commit): utf8' \
        '. "$TEST_DIRECTORY"/t3901-utf8.txt &&
+        test_when_finished "GIT_AUTHOR_NAME=\"A U Thor\"" &&
+        test_when_finished "GIT_COMMITTER_NAME=\"C O Mitter\"" &&
         echo "UTF-8" >> file &&
         git add file &&
         git commit -F "$TEST_DIRECTORY"/t3900/1-UTF-8.txt &&
 test_expect_success \
        'encode(commit): iso-8859-1' \
        '. "$TEST_DIRECTORY"/t3901-8859-1.txt &&
+        test_when_finished "GIT_AUTHOR_NAME=\"A U Thor\"" &&
+        test_when_finished "GIT_COMMITTER_NAME=\"C O Mitter\"" &&
         echo "ISO-8859-1" >> file &&
         git add file &&
         git config i18n.commitencoding ISO-8859-1 &&
+        test_when_finished "git config --unset i18n.commitencoding" &&
         git commit -F "$TEST_DIRECTORY"/t3900/ISO8859-1.txt &&
-        git config --unset i18n.commitencoding &&
         gitweb_run "p=.git;a=commit"'
 
 test_expect_success \