diff --git a/reachable.c b/reachable.c
index 6e9b810d2a5e03..0d00a91de4c848 100644
--- a/reachable.c
+++ b/reachable.c
@@ -12,6 +12,7 @@
 #include "packfile.h"
 #include "worktree.h"
 #include "object-store.h"
+#include "pack-bitmap.h"
 
 struct connectivity_progress {
 	struct progress *progress;
@@ -158,10 +159,44 @@ int add_unseen_recent_objects_to_traversal(struct rev_info *revs,
 				      FOR_EACH_OBJECT_LOCAL_ONLY);
 }
 
+static void *lookup_object_by_type(struct repository *r,
+				   const struct object_id *oid,
+				   enum object_type type)
+{
+	switch (type) {
+	case OBJ_COMMIT:
+		return lookup_commit(r, oid);
+	case OBJ_TREE:
+		return lookup_tree(r, oid);
+	case OBJ_TAG:
+		return lookup_tag(r, oid);
+	case OBJ_BLOB:
+		return lookup_blob(r, oid);
+	default:
+		die("BUG: unknown object type %d", type);
+	}
+}
+
+static int mark_object_seen(const struct object_id *oid,
+			     enum object_type type,
+			     int exclude,
+			     uint32_t name_hash,
+			     struct packed_git *found_pack,
+			     off_t found_offset)
+{
+	struct object *obj = lookup_object_by_type(the_repository, oid, type);
+	if (!obj)
+		die("unable to create object '%s'", oid_to_hex(oid));
+
+	obj->flags |= SEEN;
+	return 0;
+}
+
 void mark_reachable_objects(struct rev_info *revs, int mark_reflog,
 			    timestamp_t mark_recent, struct progress *progress)
 {
 	struct connectivity_progress cp;
+	struct bitmap_index *bitmap_git;
 
 	/*
 	 * Set up revision parsing, and mark us as being interested
@@ -188,6 +223,13 @@ void mark_reachable_objects(struct rev_info *revs, int mark_reflog,
 	cp.progress = progress;
 	cp.count = 0;
 
+	bitmap_git = prepare_bitmap_walk(revs);
+	if (bitmap_git) {
+		traverse_bitmap_commit_list(bitmap_git, mark_object_seen);
+		free_bitmap_index(bitmap_git);
+		return;
+	}
+
 	/*
 	 * Set up the revision walk - this will move all commits
 	 * from the pending list to the commit walking list.
diff --git a/t/perf/p5304-prune.sh b/t/perf/p5304-prune.sh
index 3c852084eb4330..83baedb8a49280 100755
--- a/t/perf/p5304-prune.sh
+++ b/t/perf/p5304-prune.sh
@@ -21,4 +21,15 @@ test_perf 'prune with no objects' '
 	git prune
 '
 
+test_expect_success 'repack with bitmaps' '
+	git repack -adb
+'
+
+# We have to create the object in each trial run, since otherwise
+# runs after the first see no object and just skip the traversal entirely!
+test_perf 'prune with bitmaps' '
+	echo "probably not present in repo" | git hash-object -w --stdin &&
+	git prune
+'
+
 test_done