diff --git a/Source/Private/ASTwoDimensionalArrayUtils.mm b/Source/Private/ASTwoDimensionalArrayUtils.mm
index 8b4836fe8..67267b7a9 100644
--- a/Source/Private/ASTwoDimensionalArrayUtils.mm
+++ b/Source/Private/ASTwoDimensionalArrayUtils.mm
@@ -8,9 +8,12 @@
 //
 
 #import <AsyncDisplayKit/ASAssert.h>
+#import <AsyncDisplayKit/ASCollections.h>
 #import <AsyncDisplayKit/ASInternalHelpers.h>
 #import <AsyncDisplayKit/ASTwoDimensionalArrayUtils.h>
 
+#import <vector>
+
 // Import UIKit to get [NSIndexPath indexPathForItem:inSection:] which uses
 // tagged pointers.
 #import <UIKit/UIKit.h>
@@ -63,31 +66,42 @@ void ASDeleteElementsInTwoDimensionalArrayAtIndexPaths(NSMutableArray *mutableAr
 
 NSArray<NSIndexPath *> *ASIndexPathsForTwoDimensionalArray(NSArray <NSArray *>* twoDimensionalArray)
 {
-  NSMutableArray *result = [[NSMutableArray alloc] init];
-  NSInteger section = 0;
+  NSInteger sectionCount = twoDimensionalArray.count;
+  NSInteger counts[sectionCount];
+  NSInteger totalCount = 0;
   NSInteger i = 0;
   for (NSArray *subarray in twoDimensionalArray) {
-    ASDisplayNodeCAssert([subarray isKindOfClass:[NSArray class]], @"This function expects NSArray<NSArray *> *");
-    NSInteger itemCount = subarray.count;
-    for (NSInteger item = 0; item < itemCount; item++) {
-      result[i++] = [NSIndexPath indexPathForItem:item inSection:section];
+    NSInteger count = subarray.count;
+    counts[i++] = count;
+    totalCount += count;
+  }
+  
+  // Count could be huge. Use a reserved vector rather than VLA (stack.)
+  std::vector<NSIndexPath *> indexPaths;
+  indexPaths.reserve(totalCount);
+  for (NSInteger i = 0; i < sectionCount; i++) {
+    for (NSInteger j = 0; j < counts[i]; j++) {
+      indexPaths.push_back([NSIndexPath indexPathForItem:j inSection:i]);
     }
-    section++;
   }
-  return result;
+  return [NSArray arrayByTransferring:indexPaths.data() count:totalCount];
 }
 
 NSArray *ASElementsInTwoDimensionalArray(NSArray <NSArray *>* twoDimensionalArray)
 {
-  NSMutableArray *result = [[NSMutableArray alloc] init];
-  NSInteger i = 0;
+  NSInteger totalCount = 0;
   for (NSArray *subarray in twoDimensionalArray) {
-    ASDisplayNodeCAssert([subarray isKindOfClass:[NSArray class]], @"This function expects NSArray<NSArray *> *");
-    for (id element in subarray) {
-      result[i++] = element;
+    totalCount += subarray.count;
+  }
+  
+  std::vector<id> elements;
+  elements.reserve(totalCount);
+  for (NSArray *subarray in twoDimensionalArray) {
+    for (id object in subarray) {
+      elements.push_back(object);
     }
   }
-  return result;
+  return [NSArray arrayByTransferring:elements.data() count:totalCount];
 }
 
 id ASGetElementInTwoDimensionalArray(NSArray *array, NSIndexPath *indexPath)