diff --git a/t/t7814-grep-recurse-submodules.sh b/t/t7814-grep-recurse-submodules.sh
index 828cb3ba58..3172f5b936 100755
--- a/t/t7814-grep-recurse-submodules.sh
+++ b/t/t7814-grep-recurse-submodules.sh
@@ -8,6 +8,9 @@ submodules.
 
 . ./test-lib.sh
 
+GIT_TEST_FATAL_REGISTER_SUBMODULE_ODB=1
+export GIT_TEST_FATAL_REGISTER_SUBMODULE_ODB
+
 test_expect_success 'setup directory structure and submodule' '
 	echo "(1|2)d(3|4)" >a &&
 	mkdir b &&