diff --git a/posting/index.go b/posting/index.go
index efa4eccd1b5..36aa4a0b267 100644
--- a/posting/index.go
+++ b/posting/index.go
@@ -114,7 +114,7 @@ func (txn *Txn) addIndexMutation(ctx context.Context, edge *pb.DirectedEdge,
 	token string) error {
 	key := x.IndexKey(edge.Attr, token)
 
-	plist, err := txn.Get(key)
+	plist, err := txn.cache.GetFromDelta(key)
 	if err != nil {
 		return err
 	}
@@ -169,7 +169,7 @@ func (txn *Txn) addReverseMutationHelper(ctx context.Context, plist *List,
 
 func (txn *Txn) addReverseMutation(ctx context.Context, t *pb.DirectedEdge) error {
 	key := x.ReverseKey(t.Attr, t.ValueId)
-	plist, err := txn.Get(key)
+	plist, err := txn.cache.GetFromDelta(key)
 	if err != nil {
 		return err
 	}
@@ -256,7 +256,7 @@ func (l *List) handleDeleteAll(ctx context.Context, edge *pb.DirectedEdge,
 func (txn *Txn) addCountMutation(ctx context.Context, t *pb.DirectedEdge, count uint32,
 	reverse bool) error {
 	key := x.CountKey(t.Attr, count, reverse)
-	plist, err := txn.Get(key)
+	plist, err := txn.cache.GetFromDelta(key)
 	if err != nil {
 		return err
 	}
@@ -940,7 +940,7 @@ func rebuildListType(ctx context.Context, rb *IndexRebuild) error {
 
 		// Ensure that list is in the cache run by txn. Otherwise, nothing would
 		// get updated.
-		txn.cache.SetIfAbsent(string(pl.key), pl)
+		pl = txn.cache.SetIfAbsent(string(pl.key), pl)
 		if err := pl.addMutation(ctx, txn, t); err != nil {
 			return err
 		}
diff --git a/posting/lists.go b/posting/lists.go
index 973e254945a..cc803e25e5e 100644
--- a/posting/lists.go
+++ b/posting/lists.go
@@ -221,8 +221,7 @@ func (lc *LocalCache) SetIfAbsent(key string, updated *List) *List {
 	return updated
 }
 
-// Get retrieves the cached version of the list associated with the given key.
-func (lc *LocalCache) Get(key []byte) (*List, error) {
+func (lc *LocalCache) getInternal(key []byte, readFromDisk bool) (*List, error) {
 	if lc == nil {
 		return getNew(key, pstore)
 	}
@@ -231,10 +230,21 @@ func (lc *LocalCache) Get(key []byte) (*List, error) {
 		return pl, nil
 	}
 
-	pl, err := getNew(key, pstore)
-	if err != nil {
-		return nil, err
+	var pl *List
+	if readFromDisk {
+		var err error
+		pl, err = getNew(key, pstore)
+		if err != nil {
+			return nil, err
+		}
+	} else {
+		pl = &List{
+			key:         key,
+			mutationMap: make(map[uint64]*pb.PostingList),
+			plist:       new(pb.PostingList),
+		}
 	}
+
 	// If we just brought this posting list into memory and we already have a delta for it, let's
 	// apply it before returning the list.
 	lc.RLock()
@@ -245,6 +255,18 @@ func (lc *LocalCache) Get(key []byte) (*List, error) {
 	return lc.SetIfAbsent(skey, pl), nil
 }
 
+// Get retrieves the cached version of the list associated with the given key.
+func (lc *LocalCache) Get(key []byte) (*List, error) {
+	return lc.getInternal(key, true)
+}
+
+// GetFromDelta gets the cached version of the list without reading from disk
+// and only applies the existing deltas. This is used in situations where the
+// posting list will only be modified and not read (e.g adding index mutations).
+func (lc *LocalCache) GetFromDelta(key []byte) (*List, error) {
+	return lc.getInternal(key, false)
+}
+
 // UpdateDeltasAndDiscardLists updates the delta cache before removing the stored posting lists.
 func (lc *LocalCache) UpdateDeltasAndDiscardLists() {
 	lc.Lock()