diff --git a/dot/sync/chain_sync_test.go b/dot/sync/chain_sync_test.go
index 36f18c35a8..d99afe8db6 100644
--- a/dot/sync/chain_sync_test.go
+++ b/dot/sync/chain_sync_test.go
@@ -63,7 +63,7 @@ func Test_chainSync_onBlockAnnounce(t *testing.T) {
 	t.Parallel()
 	const somePeer = peer.ID("abc")
 
-	//errTest := errors.New("test error")
+	errTest := errors.New("test error")
 	emptyTrieState := storage.NewTrieState(trie.NewEmptyTrie())
 	block1AnnounceHeader := types.NewHeader(common.Hash{}, emptyTrieState.MustRoot(trie.NoMaxInlineValueSize),
 		common.Hash{}, 1, scale.VaryingDataTypeSlice{})
@@ -80,61 +80,61 @@ func Test_chainSync_onBlockAnnounce(t *testing.T) {
 		errMessage          string
 		expectedSyncMode    chainSyncState
 	}{
-		// "announced_block_already_exists_in_disjoint_set": {
-		// 	chainSyncBuilder: func(ctrl *gomock.Controller) *chainSync {
-		// 		pendingBlocks := NewMockDisjointBlockSet(ctrl)
-		// 		pendingBlocks.EXPECT().hasBlock(block2AnnounceHeader.Hash()).Return(true)
-		// 		return &chainSync{
-		// 			stopCh:        make(chan struct{}),
-		// 			pendingBlocks: pendingBlocks,
-		// 			peerViewSet:   newPeerViewSet(0),
-		// 			workerPool:    newSyncWorkerPool(NewMockNetwork(nil), NewMockRequestMaker(nil)),
-		// 		}
-		// 	},
-		// 	peerID:              somePeer,
-		// 	blockAnnounceHeader: block2AnnounceHeader,
-		// 	errWrapped:          errAlreadyInDisjointSet,
-		// 	errMessage: fmt.Sprintf("already in disjoint set: block %s (#%d)",
-		// 		block2AnnounceHeader.Hash(), block2AnnounceHeader.Number),
-		// },
-		// "failed_to_add_announced_block_in_disjoint_set": {
-		// 	chainSyncBuilder: func(ctrl *gomock.Controller) *chainSync {
-		// 		pendingBlocks := NewMockDisjointBlockSet(ctrl)
-		// 		pendingBlocks.EXPECT().hasBlock(block2AnnounceHeader.Hash()).Return(false)
-		// 		pendingBlocks.EXPECT().addHeader(block2AnnounceHeader).Return(errTest)
-
-		// 		return &chainSync{
-		// 			stopCh:        make(chan struct{}),
-		// 			pendingBlocks: pendingBlocks,
-		// 			peerViewSet:   newPeerViewSet(0),
-		// 			workerPool:    newSyncWorkerPool(NewMockNetwork(nil), NewMockRequestMaker(nil)),
-		// 		}
-		// 	},
-		// 	peerID:              somePeer,
-		// 	blockAnnounceHeader: block2AnnounceHeader,
-		// 	errWrapped:          errTest,
-		// 	errMessage:          "while adding pending block header: test error",
-		// },
-		// "announced_block_while_in_bootstrap_mode": {
-		// 	chainSyncBuilder: func(ctrl *gomock.Controller) *chainSync {
-		// 		pendingBlocks := NewMockDisjointBlockSet(ctrl)
-		// 		pendingBlocks.EXPECT().hasBlock(block2AnnounceHeader.Hash()).Return(false)
-		// 		pendingBlocks.EXPECT().addHeader(block2AnnounceHeader).Return(nil)
-
-		// 		state := atomic.Value{}
-		// 		state.Store(bootstrap)
-
-		// 		return &chainSync{
-		// 			stopCh:        make(chan struct{}),
-		// 			pendingBlocks: pendingBlocks,
-		// 			syncMode:      state,
-		// 			peerViewSet:   newPeerViewSet(0),
-		// 			workerPool:    newSyncWorkerPool(NewMockNetwork(nil), NewMockRequestMaker(nil)),
-		// 		}
-		// 	},
-		// 	peerID:              somePeer,
-		// 	blockAnnounceHeader: block2AnnounceHeader,
-		// },
+		"announced_block_already_exists_in_disjoint_set": {
+			chainSyncBuilder: func(ctrl *gomock.Controller) *chainSync {
+				pendingBlocks := NewMockDisjointBlockSet(ctrl)
+				pendingBlocks.EXPECT().hasBlock(block2AnnounceHeader.Hash()).Return(true)
+				return &chainSync{
+					stopCh:        make(chan struct{}),
+					pendingBlocks: pendingBlocks,
+					peerViewSet:   newPeerViewSet(0),
+					workerPool:    newSyncWorkerPool(NewMockNetwork(nil), NewMockRequestMaker(nil)),
+				}
+			},
+			peerID:              somePeer,
+			blockAnnounceHeader: block2AnnounceHeader,
+			errWrapped:          errAlreadyInDisjointSet,
+			errMessage: fmt.Sprintf("already in disjoint set: block %s (#%d)",
+				block2AnnounceHeader.Hash(), block2AnnounceHeader.Number),
+		},
+		"failed_to_add_announced_block_in_disjoint_set": {
+			chainSyncBuilder: func(ctrl *gomock.Controller) *chainSync {
+				pendingBlocks := NewMockDisjointBlockSet(ctrl)
+				pendingBlocks.EXPECT().hasBlock(block2AnnounceHeader.Hash()).Return(false)
+				pendingBlocks.EXPECT().addHeader(block2AnnounceHeader).Return(errTest)
+
+				return &chainSync{
+					stopCh:        make(chan struct{}),
+					pendingBlocks: pendingBlocks,
+					peerViewSet:   newPeerViewSet(0),
+					workerPool:    newSyncWorkerPool(NewMockNetwork(nil), NewMockRequestMaker(nil)),
+				}
+			},
+			peerID:              somePeer,
+			blockAnnounceHeader: block2AnnounceHeader,
+			errWrapped:          errTest,
+			errMessage:          "while adding pending block header: test error",
+		},
+		"announced_block_while_in_bootstrap_mode": {
+			chainSyncBuilder: func(ctrl *gomock.Controller) *chainSync {
+				pendingBlocks := NewMockDisjointBlockSet(ctrl)
+				pendingBlocks.EXPECT().hasBlock(block2AnnounceHeader.Hash()).Return(false)
+				pendingBlocks.EXPECT().addHeader(block2AnnounceHeader).Return(nil)
+
+				state := atomic.Value{}
+				state.Store(bootstrap)
+
+				return &chainSync{
+					stopCh:        make(chan struct{}),
+					pendingBlocks: pendingBlocks,
+					syncMode:      state,
+					peerViewSet:   newPeerViewSet(0),
+					workerPool:    newSyncWorkerPool(NewMockNetwork(nil), NewMockRequestMaker(nil)),
+				}
+			},
+			peerID:              somePeer,
+			blockAnnounceHeader: block2AnnounceHeader,
+		},
 		"announced_block_while_in_tip_mode": {
 			chainSyncBuilder: func(ctrl *gomock.Controller) *chainSync {
 				pendingBlocksMock := NewMockDisjointBlockSet(ctrl)