diff --git a/Parchment/Classes/PagingViewController.swift b/Parchment/Classes/PagingViewController.swift
index 12951403..7c7c9654 100644
--- a/Parchment/Classes/PagingViewController.swift
+++ b/Parchment/Classes/PagingViewController.swift
@@ -543,9 +543,15 @@ open class PagingViewController<T: PagingItem>:
 
   private func generateItemsForIndexedDataSource() -> [T] {
     let numberOfItems = dataSource?.numberOfViewControllers(in: self) ?? 0
-    return (0..<numberOfItems).enumerated().compactMap{
-      dataSource?.pagingViewController(self, pagingItemForIndex: $0.offset)
-    }
+    #if swift(>=4.1)
+      return (0..<numberOfItems).enumerated().compactMap{
+        dataSource?.pagingViewController(self, pagingItemForIndex: $0.offset)
+      }
+    #else
+      return (0..<numberOfItems).enumerated().flatMap{
+        dataSource?.pagingViewController(self, pagingItemForIndex: $0.offset)
+      }
+    #endif
   }
   
   private func configureDataSource() {