diff --git a/builtin/clone.c b/builtin/clone.c
index 5b9ebe9..a693e6c 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -1149,13 +1149,11 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		transport->server_options = &server_options;
 
 	if (filter_options.choice) {
-		struct strbuf expanded_filter_spec = STRBUF_INIT;
-		expand_list_objects_filter_spec(&filter_options,
-						&expanded_filter_spec);
+		const char *spec =
+			expand_list_objects_filter_spec(&filter_options);
 		transport_set_option(transport, TRANS_OPT_LIST_OBJECTS_FILTER,
-				     expanded_filter_spec.buf);
+				     spec);
 		transport_set_option(transport, TRANS_OPT_FROM_PROMISOR, "1");
-		strbuf_release(&expanded_filter_spec);
 	}
 
 	if (transport->smart_options && !deepen && !filter_options.choice)
diff --git a/builtin/fetch.c b/builtin/fetch.c
index 4ba63d5..dee89e1 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -1188,13 +1188,10 @@ static struct transport *prepare_transport(struct remote *remote, int deepen)
 	if (update_shallow)
 		set_option(transport, TRANS_OPT_UPDATE_SHALLOW, "yes");
 	if (filter_options.choice) {
-		struct strbuf expanded_filter_spec = STRBUF_INIT;
-		expand_list_objects_filter_spec(&filter_options,
-						&expanded_filter_spec);
-		set_option(transport, TRANS_OPT_LIST_OBJECTS_FILTER,
-			   expanded_filter_spec.buf);
+		const char *spec =
+			expand_list_objects_filter_spec(&filter_options);
+		set_option(transport, TRANS_OPT_LIST_OBJECTS_FILTER, spec);
 		set_option(transport, TRANS_OPT_FROM_PROMISOR, "1");
-		strbuf_release(&expanded_filter_spec);
 	}
 	if (negotiation_tip.nr) {
 		if (transport->smart_options)
diff --git a/builtin/rev-list.c b/builtin/rev-list.c
index 660172b..68acbe8 100644
--- a/builtin/rev-list.c
+++ b/builtin/rev-list.c
@@ -466,8 +466,10 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix)
 				die(_("object filtering requires --objects"));
 			if (filter_options.choice == LOFC_SPARSE_OID &&
 			    !filter_options.sparse_oid_value)
-				die(_("invalid sparse value '%s'"),
-				    filter_options.filter_spec);
+				die(
+					_("invalid sparse value '%s'"),
+					list_objects_filter_spec(
+						&filter_options));
 			continue;
 		}
 		if (!strcmp(arg, ("--no-" CL_ARG__FILTER))) {
diff --git a/fetch-pack.c b/fetch-pack.c
index 1c10f54..72e13b0 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -339,12 +339,9 @@ static int find_common(struct fetch_negotiator *negotiator,
 		}
 	}
 	if (server_supports_filtering && args->filter_options.choice) {
-		struct strbuf expanded_filter_spec = STRBUF_INIT;
-		expand_list_objects_filter_spec(&args->filter_options,
-						&expanded_filter_spec);
-		packet_buf_write(&req_buf, "filter %s",
-				 expanded_filter_spec.buf);
-		strbuf_release(&expanded_filter_spec);
+		const char *spec =
+			expand_list_objects_filter_spec(&args->filter_options);
+		packet_buf_write(&req_buf, "filter %s", spec);
 	}
 	packet_buf_flush(&req_buf);
 	state_len = req_buf.len;
@@ -1099,7 +1096,7 @@ static int add_haves(struct fetch_negotiator *negotiator,
 }
 
 static int send_fetch_request(struct fetch_negotiator *negotiator, int fd_out,
-			      const struct fetch_pack_args *args,
+			      struct fetch_pack_args *args,
 			      const struct ref *wants, struct oidset *common,
 			      int *haves_to_send, int *in_vain,
 			      int sideband_all)
@@ -1140,13 +1137,10 @@ static int send_fetch_request(struct fetch_negotiator *negotiator, int fd_out,
 	/* Add filter */
 	if (server_supports_feature("fetch", "filter", 0) &&
 	    args->filter_options.choice) {
-		struct strbuf expanded_filter_spec = STRBUF_INIT;
+		const char *spec =
+			expand_list_objects_filter_spec(&args->filter_options);
 		print_verbose(args, _("Server supports filter"));
-		expand_list_objects_filter_spec(&args->filter_options,
-						&expanded_filter_spec);
-		packet_buf_write(&req_buf, "filter %s",
-				 expanded_filter_spec.buf);
-		strbuf_release(&expanded_filter_spec);
+		packet_buf_write(&req_buf, "filter %s", spec);
 	} else if (args->filter_options.choice) {
 		warning("filtering not recognized by server, ignoring");
 	}
diff --git a/list-objects-filter-options.c b/list-objects-filter-options.c
index 5fe2814..01c0f13 100644
--- a/list-objects-filter-options.c
+++ b/list-objects-filter-options.c
@@ -184,7 +184,7 @@ int parse_list_objects_filter(struct list_objects_filter_options *filter_options
 	struct strbuf buf = STRBUF_INIT;
 	if (filter_options->choice)
 		die(_("multiple filter-specs cannot be combined"));
-	filter_options->filter_spec = strdup(arg);
+	string_list_append(&filter_options->filter_spec, xstrdup(arg));
 	if (gently_parse_list_objects_filter(filter_options, arg, &buf))
 		die("%s", buf.buf);
 	return 0;
@@ -203,19 +203,36 @@ int opt_parse_list_objects_filter(const struct option *opt,
 	return parse_list_objects_filter(filter_options, arg);
 }
 
-void expand_list_objects_filter_spec(
-	const struct list_objects_filter_options *filter,
-	struct strbuf *expanded_spec)
+const char *list_objects_filter_spec(struct list_objects_filter_options *filter)
 {
-	strbuf_init(expanded_spec, strlen(filter->filter_spec));
-	if (filter->choice == LOFC_BLOB_LIMIT)
-		strbuf_addf(expanded_spec, "blob:limit=%lu",
+	if (!filter->filter_spec.nr)
+		BUG("no filter_spec available for this filter");
+	if (filter->filter_spec.nr != 1) {
+		struct strbuf concatted = STRBUF_INIT;
+		strbuf_add_separated_string_list(
+			&concatted, "", &filter->filter_spec);
+		string_list_clear(&filter->filter_spec, /*free_util=*/0);
+		string_list_append(
+			&filter->filter_spec, strbuf_detach(&concatted, NULL));
+	}
+
+	return filter->filter_spec.items[0].string;
+}
+
+const char *expand_list_objects_filter_spec(
+	struct list_objects_filter_options *filter)
+{
+	if (filter->choice == LOFC_BLOB_LIMIT) {
+		struct strbuf expanded_spec = STRBUF_INIT;
+		strbuf_addf(&expanded_spec, "blob:limit=%lu",
 			    filter->blob_limit_value);
-	else if (filter->choice == LOFC_TREE_DEPTH)
-		strbuf_addf(expanded_spec, "tree:%lu",
-			    filter->tree_exclude_depth);
-	else
-		strbuf_addstr(expanded_spec, filter->filter_spec);
+		string_list_clear(&filter->filter_spec, /*free_util=*/0);
+		string_list_append(
+			&filter->filter_spec,
+			strbuf_detach(&expanded_spec, NULL));
+	}
+
+	return list_objects_filter_spec(filter);
 }
 
 void list_objects_filter_release(
@@ -225,7 +242,7 @@ void list_objects_filter_release(
 
 	if (!filter_options)
 		return;
-	free(filter_options->filter_spec);
+	string_list_clear(&filter_options->filter_spec, /*free_util=*/0);
 	free(filter_options->sparse_oid_value);
 	for (sub = 0; sub < filter_options->sub_nr; sub++)
 		list_objects_filter_release(&filter_options->sub[sub]);
@@ -235,7 +252,7 @@ void list_objects_filter_release(
 
 void partial_clone_register(
 	const char *remote,
-	const struct list_objects_filter_options *filter_options)
+	struct list_objects_filter_options *filter_options)
 {
 	/*
 	 * Record the name of the partial clone remote in the
@@ -258,7 +275,7 @@ void partial_clone_register(
 	 * the default for subsequent fetches from this remote.
 	 */
 	core_partial_clone_filter_default =
-		xstrdup(filter_options->filter_spec);
+		xstrdup(expand_list_objects_filter_spec(filter_options));
 	git_config_set("core.partialclonefilter",
 		       core_partial_clone_filter_default);
 }
@@ -274,7 +291,8 @@ void partial_clone_get_default_filter_spec(
 	if (!core_partial_clone_filter_default)
 		return;
 
-	filter_options->filter_spec = strdup(core_partial_clone_filter_default);
+	string_list_append(&filter_options->filter_spec,
+			   core_partial_clone_filter_default);
 	gently_parse_list_objects_filter(filter_options,
 					 core_partial_clone_filter_default,
 					 &errbuf);
diff --git a/list-objects-filter-options.h b/list-objects-filter-options.h
index 789faef..bb33303 100644
--- a/list-objects-filter-options.h
+++ b/list-objects-filter-options.h
@@ -2,7 +2,7 @@
 #define LIST_OBJECTS_FILTER_OPTIONS_H
 
 #include "parse-options.h"
-#include "strbuf.h"
+#include "string-list.h"
 
 /*
  * The list of defined filters for list-objects.
@@ -24,8 +24,10 @@ struct list_objects_filter_options {
 	 * commands that launch filtering sub-processes, or for communication
 	 * over the network, don't use this value; use the result of
 	 * expand_list_objects_filter_spec() instead.
+	 * To get the raw filter spec given by the user, use the result of
+	 * list_objects_filter_spec().
 	 */
-	char *filter_spec;
+	struct string_list filter_spec;
 
 	/*
 	 * 'choice' is determined by parsing the filter-spec.  This indicates
@@ -76,13 +78,22 @@ int opt_parse_list_objects_filter(const struct option *opt,
 /*
  * Translates abbreviated numbers in the filter's filter_spec into their
  * fully-expanded forms (e.g., "limit:blob=1k" becomes "limit:blob=1024").
+ * Returns a string owned by the list_objects_filter_options object.
  *
- * This form should be used instead of the raw filter_spec field when
- * communicating with a remote process or subprocess.
+ * This form should be used instead of the raw list_objects_filter_spec()
+ * value when communicating with a remote process or subprocess.
  */
-void expand_list_objects_filter_spec(
-	const struct list_objects_filter_options *filter,
-	struct strbuf *expanded_spec);
+const char *expand_list_objects_filter_spec(
+	struct list_objects_filter_options *filter);
+
+/*
+ * Returns the filter spec string more or less in the form as the user
+ * entered it. This form of the filter_spec can be used in user-facing
+ * messages.  Returns a string owned by the list_objects_filter_options
+ * object.
+ */
+const char *list_objects_filter_spec(
+	struct list_objects_filter_options *filter);
 
 void list_objects_filter_release(
 	struct list_objects_filter_options *filter_options);
@@ -96,7 +107,7 @@ static inline void list_objects_filter_set_no_filter(
 
 void partial_clone_register(
 	const char *remote,
-	const struct list_objects_filter_options *filter_options);
+	struct list_objects_filter_options *filter_options);
 void partial_clone_get_default_filter_spec(
 	struct list_objects_filter_options *filter_options);
 
diff --git a/t/t6112-rev-list-filters-objects.sh b/t/t6112-rev-list-filters-objects.sh
index 05d4f2e..27ba157 100755
--- a/t/t6112-rev-list-filters-objects.sh
+++ b/t/t6112-rev-list-filters-objects.sh
@@ -590,11 +590,4 @@
 	grep "blob:limit=1024" trace
 '
 
-test_expect_success 'expand tree depth limit in protocol' '
-	GIT_TRACE_PACKET="$(pwd)/tree_trace" git -c protocol.version=2 clone \
-		--filter=tree:0k "file://$(pwd)/r2" tree &&
-	! grep "tree:0k" tree_trace &&
-	grep "tree:0" tree_trace
-'
-
 test_done
diff --git a/transport-helper.c b/transport-helper.c
index c7e17ec..0a34544 100644
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -682,13 +682,9 @@ static int fetch(struct transport *transport,
 		set_helper_option(transport, "update-shallow", "true");
 
 	if (data->transport_options.filter_options.choice) {
-		struct strbuf expanded_filter_spec = STRBUF_INIT;
-		expand_list_objects_filter_spec(
-			&data->transport_options.filter_options,
-			&expanded_filter_spec);
-		set_helper_option(transport, "filter",
-				  expanded_filter_spec.buf);
-		strbuf_release(&expanded_filter_spec);
+		const char *spec = expand_list_objects_filter_spec(
+			&data->transport_options.filter_options);
+		set_helper_option(transport, "filter", spec);
 	}
 
 	if (data->transport_options.negotiation_tips)
diff --git a/upload-pack.c b/upload-pack.c
index 4d2129e..d404d88 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -140,18 +140,17 @@ static void create_pack_file(const struct object_array *have_obj,
 		argv_array_push(&pack_objects.args, "--delta-base-offset");
 	if (use_include_tag)
 		argv_array_push(&pack_objects.args, "--include-tag");
-	if (filter_options.filter_spec) {
-		struct strbuf expanded_filter_spec = STRBUF_INIT;
-		expand_list_objects_filter_spec(&filter_options,
-						&expanded_filter_spec);
+	if (filter_options.choice) {
+		const char *spec =
+			expand_list_objects_filter_spec(&filter_options);
 		if (pack_objects.use_shell) {
 			struct strbuf buf = STRBUF_INIT;
-			sq_quote_buf(&buf, expanded_filter_spec.buf);
+			sq_quote_buf(&buf, spec);
 			argv_array_pushf(&pack_objects.args, "--filter=%s", buf.buf);
 			strbuf_release(&buf);
 		} else {
 			argv_array_pushf(&pack_objects.args, "--filter=%s",
-					 expanded_filter_spec.buf);
+					 spec);
 		}
 	}