diff --git a/t/lib-httpd.sh b/t/lib-httpd.sh
index a8729f8232..3eb665f4d6 100644
--- a/t/lib-httpd.sh
+++ b/t/lib-httpd.sh
@@ -91,6 +91,7 @@ HTTPD_DOCUMENT_ROOT_PATH=$HTTPD_ROOT_PATH/www
 # hack to suppress apache PassEnv warnings
 GIT_VALGRIND=$GIT_VALGRIND; export GIT_VALGRIND
 GIT_VALGRIND_OPTIONS=$GIT_VALGRIND_OPTIONS; export GIT_VALGRIND_OPTIONS
+GIT_TEST_SIDEBAND_ALL=$GIT_TEST_SIDEBAND_ALL; export GIT_TEST_SIDEBAND_ALL
 GIT_TRACE=$GIT_TRACE; export GIT_TRACE
 
 if ! test -x "$LIB_HTTPD_PATH"