diff --git a/pack-bitmap.c b/pack-bitmap.c
index 982e286bac..aaa2d9a104 100644
--- a/pack-bitmap.c
+++ b/pack-bitmap.c
@@ -354,8 +354,8 @@ static int open_midx_bitmap_1(struct bitmap_index *bitmap_git,
 	if (bitmap_git->pack || bitmap_git->midx) {
 		struct strbuf buf = STRBUF_INIT;
 		get_midx_filename(&buf, midx->object_dir);
-		/* ignore extra bitmap file; we can only handle one */
-		warning(_("ignoring extra bitmap file: '%s'"), buf.buf);
+		trace2_data_string("bitmap", the_repository,
+				   "ignoring extra midx bitmap file", buf.buf);
 		close(fd);
 		strbuf_release(&buf);
 		return -1;
@@ -429,8 +429,8 @@ static int open_pack_bitmap_1(struct bitmap_index *bitmap_git, struct packed_git
 	}
 
 	if (bitmap_git->pack || bitmap_git->midx) {
-		/* ignore extra bitmap file; we can only handle one */
-		warning(_("ignoring extra bitmap file: '%s'"), packfile->pack_name);
+		trace2_data_string("bitmap", the_repository,
+				   "ignoring extra bitmap file", packfile->pack_name);
 		close(fd);
 		return -1;
 	}
@@ -455,6 +455,8 @@ static int open_pack_bitmap_1(struct bitmap_index *bitmap_git, struct packed_git
 		return -1;
 	}
 
+	trace2_data_string("bitmap", the_repository, "opened bitmap file",
+			   packfile->pack_name);
 	return 0;
 }
 
diff --git a/t/t5310-pack-bitmaps.sh b/t/t5310-pack-bitmaps.sh
index 6d693eef82..7d8dee41b0 100755
--- a/t/t5310-pack-bitmaps.sh
+++ b/t/t5310-pack-bitmaps.sh
@@ -428,8 +428,9 @@ test_bitmap_cases () {
 			test_line_count = 2 packs &&
 			test_line_count = 2 bitmaps &&
 
-			git rev-list --use-bitmap-index HEAD 2>err &&
-			grep "ignoring extra bitmap file" err
+			GIT_TRACE2_EVENT=$(pwd)/trace2.txt git rev-list --use-bitmap-index HEAD &&
+			grep "opened bitmap" trace2.txt &&
+			grep "ignoring extra bitmap" trace2.txt
 		)
 	'
 }