diff --git a/tsdb/head_append_v2_test.go b/tsdb/head_append_v2_test.go
index b98ee5c10d..abf0bd94d3 100644
--- a/tsdb/head_append_v2_test.go
+++ b/tsdb/head_append_v2_test.go
@@ -608,10 +608,10 @@ func TestHeadAppenderV2_Delete_e2e(t *testing.T) {
 				sexp := expSs.At()
 				sres := ss.At()
 				require.Equal(t, sexp.Labels(), sres.Labels())
-				smplExp, errExp := storage.ExpandSamples(sexp.Iterator(nil), nil)
-				smplRes, errRes := storage.ExpandSamples(sres.Iterator(nil), nil)
+				smplExp, errExp := storage.ExpandSamples(sexp.Iterator(nil), newSample)
+				smplRes, errRes := storage.ExpandSamples(sres.Iterator(nil), newSample)
 				require.Equal(t, errExp, errRes)
-				require.Equal(t, smplExp, smplRes)
+				requireEqualSamples(t, sexp.Labels().String(), smplExp, smplRes)
 			}
 			require.NoError(t, ss.Err())
 			require.Empty(t, ss.Warnings())
@@ -1333,22 +1333,32 @@ func TestDataMissingOnQueryDuringCompaction_AppenderV2(t *testing.T) {
 	q, err := db.Querier(mint, maxt)
 	require.NoError(t, err)
 
-	var wg sync.WaitGroup
-	wg.Go(func() {
-		// Compacting head while the querier spans the compaction time.
-		require.NoError(t, db.Compact(ctx))
-		require.NotEmpty(t, db.Blocks())
-	})
+	truncationStarted := make(chan struct{})
+	db.head.memTruncationCallBack = func() {
+		close(truncationStarted)
+	}
 
-	// Give enough time for compaction to finish.
-	// We expect it to be blocked until querier is closed.
-	<-time.After(3 * time.Second)
+	compactDone := make(chan error, 1)
+	go func() {
+		// Compacting head while the querier spans the compaction time.
+		compactDone <- db.Compact(ctx)
+	}()
+
+	select {
+	case <-truncationStarted:
+	case err := <-compactDone:
+		require.NoError(t, err)
+		require.FailNow(t, "compaction finished before head truncation started")
+	case <-time.After(10 * time.Second):
+		require.FailNow(t, "timed out waiting for head truncation to start")
+	}
 
 	// Querying the querier that was got before compaction.
 	series := query(t, q, labels.MustNewMatcher(labels.MatchEqual, "a", "b"))
 	require.Equal(t, map[string][]chunks.Sample{`{a="b"}`: expSamples}, series)
 
-	wg.Wait()
+	require.NoError(t, <-compactDone)
+	require.NotEmpty(t, db.Blocks())
 }
 
 func TestIsQuerierCollidingWithTruncation_AppenderV2(t *testing.T) {
diff --git a/tsdb/head_test.go b/tsdb/head_test.go
index d4279185fe..aa2c39ffee 100644
--- a/tsdb/head_test.go
+++ b/tsdb/head_test.go
@@ -2158,10 +2158,10 @@ func TestDelete_e2e(t *testing.T) {
 				sexp := expSs.At()
 				sres := ss.At()
 				require.Equal(t, sexp.Labels(), sres.Labels())
-				smplExp, errExp := storage.ExpandSamples(sexp.Iterator(nil), nil)
-				smplRes, errRes := storage.ExpandSamples(sres.Iterator(nil), nil)
+				smplExp, errExp := storage.ExpandSamples(sexp.Iterator(nil), newSample)
+				smplRes, errRes := storage.ExpandSamples(sres.Iterator(nil), newSample)
 				require.Equal(t, errExp, errRes)
-				require.Equal(t, smplExp, smplRes)
+				requireEqualSamples(t, sexp.Labels().String(), smplExp, smplRes)
 			}
 			require.NoError(t, ss.Err())
 			require.Empty(t, ss.Warnings())