diff --git a/builtin/grep.c b/builtin/grep.c
index bad9c0a3d5..0cc671f7d6 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -393,18 +393,20 @@ static void run_pager(struct grep_opt *opt, const char *prefix)
 		exit(status);
 }
 
-static int grep_cache(struct grep_opt *opt, struct repository *repo,
+static int grep_cache(struct grep_opt *opt,
 		      const struct pathspec *pathspec, int cached);
 static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
 		     struct tree_desc *tree, struct strbuf *base, int tn_len,
-		     int check_attr, struct repository *repo);
+		     int check_attr);
 
-static int grep_submodule(struct grep_opt *opt, struct repository *superproject,
+static int grep_submodule(struct grep_opt *opt,
 			  const struct pathspec *pathspec,
 			  const struct object_id *oid,
 			  const char *filename, const char *path)
 {
+	struct repository *superproject = opt->repo;
 	struct repository submodule;
+	struct grep_opt subopt;
 	int hit;
 
 	/*
@@ -440,6 +442,9 @@ static int grep_submodule(struct grep_opt *opt, struct repository *superproject,
 	add_to_alternates_memory(submodule.objects->odb->path);
 	grep_read_unlock();
 
+	memcpy(&subopt, opt, sizeof(subopt));
+	subopt.repo = &submodule;
+
 	if (oid) {
 		struct object *object;
 		struct tree_desc tree;
@@ -461,21 +466,22 @@ static int grep_submodule(struct grep_opt *opt, struct repository *superproject,
 		strbuf_addch(&base, '/');
 
 		init_tree_desc(&tree, data, size);
-		hit = grep_tree(opt, pathspec, &tree, &base, base.len,
-				object->type == OBJ_COMMIT, &submodule);
+		hit = grep_tree(&subopt, pathspec, &tree, &base, base.len,
+				object->type == OBJ_COMMIT);
 		strbuf_release(&base);
 		free(data);
 	} else {
-		hit = grep_cache(opt, &submodule, pathspec, 1);
+		hit = grep_cache(&subopt, pathspec, 1);
 	}
 
 	repo_clear(&submodule);
 	return hit;
 }
 
-static int grep_cache(struct grep_opt *opt, struct repository *repo,
+static int grep_cache(struct grep_opt *opt,
 		      const struct pathspec *pathspec, int cached)
 {
+	struct repository *repo = opt->repo;
 	int hit = 0;
 	int nr;
 	struct strbuf name = STRBUF_INIT;
@@ -513,7 +519,7 @@ static int grep_cache(struct grep_opt *opt, struct repository *repo,
 			}
 		} else if (recurse_submodules && S_ISGITLINK(ce->ce_mode) &&
 			   submodule_path_match(repo->index, pathspec, name.buf, NULL)) {
-			hit |= grep_submodule(opt, repo, pathspec, NULL, ce->name, ce->name);
+			hit |= grep_submodule(opt, pathspec, NULL, ce->name, ce->name);
 		} else {
 			continue;
 		}
@@ -535,8 +541,9 @@ static int grep_cache(struct grep_opt *opt, struct repository *repo,
 
 static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
 		     struct tree_desc *tree, struct strbuf *base, int tn_len,
-		     int check_attr, struct repository *repo)
+		     int check_attr)
 {
+	struct repository *repo = opt->repo;
 	int hit = 0;
 	enum interesting match = entry_not_interesting;
 	struct name_entry entry;
@@ -582,10 +589,10 @@ static int grep_tree(struct grep_opt *opt, const struct pathspec *pathspec,
 			strbuf_addch(base, '/');
 			init_tree_desc(&sub, data, size);
 			hit |= grep_tree(opt, pathspec, &sub, base, tn_len,
-					 check_attr, repo);
+					 check_attr);
 			free(data);
 		} else if (recurse_submodules && S_ISGITLINK(entry.mode)) {
-			hit |= grep_submodule(opt, repo, pathspec, entry.oid,
+			hit |= grep_submodule(opt, pathspec, entry.oid,
 					      base->buf, base->buf + tn_len);
 		}
 
@@ -627,7 +634,7 @@ static int grep_object(struct grep_opt *opt, const struct pathspec *pathspec,
 		}
 		init_tree_desc(&tree, data, size);
 		hit = grep_tree(opt, pathspec, &tree, &base, base.len,
-				obj->type == OBJ_COMMIT, the_repository);
+				obj->type == OBJ_COMMIT);
 		strbuf_release(&base);
 		free(data);
 		return hit;
@@ -644,12 +651,12 @@ static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec,
 
 	for (i = 0; i < nr; i++) {
 		struct object *real_obj;
-		real_obj = deref_tag(the_repository, list->objects[i].item,
+		real_obj = deref_tag(opt->repo, list->objects[i].item,
 				     NULL, 0);
 
 		/* load the gitmodules file for this rev */
 		if (recurse_submodules) {
-			submodule_free(the_repository);
+			submodule_free(opt->repo);
 			gitmodules_config_oid(&real_obj->oid);
 		}
 		if (grep_object(opt, pathspec, real_obj, list->objects[i].name,
@@ -674,9 +681,9 @@ static int grep_directory(struct grep_opt *opt, const struct pathspec *pathspec,
 	if (exc_std)
 		setup_standard_excludes(&dir);
 
-	fill_directory(&dir, &the_index, pathspec);
+	fill_directory(&dir, opt->repo->index, pathspec);
 	for (i = 0; i < dir.nr; i++) {
-		if (!dir_path_match(&the_index, dir.entries[i], pathspec, 0, NULL))
+		if (!dir_path_match(opt->repo->index, dir.entries[i], pathspec, 0, NULL))
 			continue;
 		hit |= grep_file(opt, dir.entries[i]->name);
 		if (hit && opt->status_only)
@@ -1117,7 +1124,7 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 		if (!cached)
 			setup_work_tree();
 
-		hit = grep_cache(&opt, the_repository, &pathspec, cached);
+		hit = grep_cache(&opt, &pathspec, cached);
 	} else {
 		if (cached)
 			die(_("both --cached and trees are given"));