diff --git a/internal/db/sqlite/db_local_test.go b/internal/db/sqlite/db_local_test.go
index ed0349867..1487f8266 100644
--- a/internal/db/sqlite/db_local_test.go
+++ b/internal/db/sqlite/db_local_test.go
@@ -9,6 +9,7 @@ package sqlite
 import (
 	"testing"
 
+	"github.com/syncthing/syncthing/internal/db"
 	"github.com/syncthing/syncthing/internal/itererr"
 	"github.com/syncthing/syncthing/lib/protocol"
 )
@@ -138,6 +139,211 @@ func TestBlocksDeleted(t *testing.T) {
 	}
 }
 
+func TestDropBlockIndex(t *testing.T) {
+	t.Parallel()
+
+	sdb, err := Open(t.TempDir())
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { sdb.Close() })
+
+	// Insert files with blocks
+	files := []protocol.FileInfo{
+		genFile("a", 3, 0),
+		genFile("b", 2, 0),
+	}
+	if err := sdb.Update(folderID, protocol.LocalDeviceID, files); err != nil {
+		t.Fatal(err)
+	}
+
+	// Verify blocks exist
+	hits, err := itererr.Collect(sdb.AllLocalBlocksWithHash(folderID, files[0].Blocks[0].Hash))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(hits) == 0 {
+		t.Fatal("expected block hits before drop")
+	}
+
+	// Drop the block index
+	if err := sdb.DropBlockIndex(folderID); err != nil {
+		t.Fatal(err)
+	}
+
+	// Verify blocks are gone
+	hits, err = itererr.Collect(sdb.AllLocalBlocksWithHash(folderID, files[0].Blocks[0].Hash))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(hits) != 0 {
+		t.Fatal("expected no block hits after drop")
+	}
+
+	// Dropping again should be a no-op (already empty)
+	if err := sdb.DropBlockIndex(folderID); err != nil {
+		t.Fatal(err)
+	}
+
+	// Dropping a nonexistent folder should be fine
+	if err := sdb.DropBlockIndex("nonexistent"); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestPopulateBlockIndex(t *testing.T) {
+	t.Parallel()
+
+	sdb, err := Open(t.TempDir())
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { sdb.Close() })
+
+	// Insert files with blocks
+	files := []protocol.FileInfo{
+		genFile("a", 3, 0),
+		genFile("b", 2, 0),
+	}
+	if err := sdb.Update(folderID, protocol.LocalDeviceID, files); err != nil {
+		t.Fatal(err)
+	}
+
+	// Collect the original block entries for comparison
+	origHitsA, err := itererr.Collect(sdb.AllLocalBlocksWithHash(folderID, files[0].Blocks[0].Hash))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(origHitsA) != 1 {
+		t.Fatal("expected one hit for block a[0]")
+	}
+
+	// Drop the block index
+	if err := sdb.DropBlockIndex(folderID); err != nil {
+		t.Fatal(err)
+	}
+
+	// Populate it back from existing blocklists
+	if err := sdb.PopulateBlockIndex(folderID); err != nil {
+		t.Fatal(err)
+	}
+
+	// Verify all blocks are back
+	for i, f := range files {
+		for j, b := range f.Blocks {
+			hits, err := itererr.Collect(sdb.AllLocalBlocksWithHash(folderID, b.Hash))
+			if err != nil {
+				t.Fatal(err)
+			}
+			if len(hits) == 0 {
+				t.Errorf("file %d block %d: expected hits after populate", i, j)
+			}
+		}
+	}
+
+	// Populating again should be a no-op (not empty)
+	if err := sdb.PopulateBlockIndex(folderID); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestPopulateBlockIndexSkipsRemoteFiles(t *testing.T) {
+	t.Parallel()
+
+	sdb, err := Open(t.TempDir())
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { sdb.Close() })
+
+	// Insert a local file (blocks indexed) and a remote file (blocks not indexed)
+	localFile := genFile("local", 2, 0)
+	if err := sdb.Update(folderID, protocol.LocalDeviceID, []protocol.FileInfo{localFile}); err != nil {
+		t.Fatal(err)
+	}
+	remoteFile := genFile("remote", 2, 1)
+	if err := sdb.Update(folderID, protocol.DeviceID{42}, []protocol.FileInfo{remoteFile}); err != nil {
+		t.Fatal(err)
+	}
+
+	// Drop and repopulate
+	if err := sdb.DropBlockIndex(folderID); err != nil {
+		t.Fatal(err)
+	}
+	if err := sdb.PopulateBlockIndex(folderID); err != nil {
+		t.Fatal(err)
+	}
+
+	// Local file blocks should be present
+	hits, err := itererr.Collect(sdb.AllLocalBlocksWithHash(folderID, localFile.Blocks[0].Hash))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(hits) == 0 {
+		t.Error("expected hits for local file blocks")
+	}
+
+	// Remote file blocks should not be present (blocks are only
+	// indexed for local files)
+	hits, err = itererr.Collect(sdb.AllLocalBlocksWithHash(folderID, remoteFile.Blocks[0].Hash))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(hits) != 0 {
+		t.Error("expected no hits for remote file blocks")
+	}
+}
+
+func TestSkipBlockIndexOnUpdate(t *testing.T) {
+	t.Parallel()
+
+	sdb, err := Open(t.TempDir())
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { sdb.Close() })
+
+	// Insert a file with SkipBlockIndex
+	file := genFile("a", 3, 0)
+	if err := sdb.Update(folderID, protocol.LocalDeviceID, []protocol.FileInfo{file}, db.WithSkipBlockIndex()); err != nil {
+		t.Fatal(err)
+	}
+
+	// Blocks should not be indexed
+	hits, err := itererr.Collect(sdb.AllLocalBlocksWithHash(folderID, file.Blocks[0].Hash))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(hits) != 0 {
+		t.Fatal("expected no block hits with SkipBlockIndex")
+	}
+
+	// The blocklist should still be stored (file info is retrievable with blocks)
+	fi, ok, err := sdb.GetDeviceFile(folderID, protocol.LocalDeviceID, "a")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !ok {
+		t.Fatal("file not found")
+	}
+	if len(fi.Blocks) != 3 {
+		t.Fatalf("expected 3 blocks in file info, got %d", len(fi.Blocks))
+	}
+
+	// Populate should fill in the blocks
+	if err := sdb.PopulateBlockIndex(folderID); err != nil {
+		t.Fatal(err)
+	}
+
+	hits, err = itererr.Collect(sdb.AllLocalBlocksWithHash(folderID, file.Blocks[0].Hash))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(hits) != 1 {
+		t.Fatal("expected one hit after populate")
+	}
+}
+
 func TestRemoteSequence(t *testing.T) {
 	t.Parallel()