diff --git a/src/mscorlib/shared/System/Collections/Generic/Dictionary.cs b/src/mscorlib/shared/System/Collections/Generic/Dictionary.cs
index 827cc24ac247..f0e892859ed1 100644
--- a/src/mscorlib/shared/System/Collections/Generic/Dictionary.cs
+++ b/src/mscorlib/shared/System/Collections/Generic/Dictionary.cs
@@ -315,7 +315,7 @@ private void CopyTo(KeyValuePair<TKey, TValue>[] array, int index)
             {
                 if (entries[i].hashCode >= 0)
                 {
-                    array[index + i] = new KeyValuePair<TKey, TValue>(entries[i].key, entries[i].value);
+                    array[index++] = new KeyValuePair<TKey, TValue>(entries[i].key, entries[i].value);
                 }
             }
         }
@@ -822,7 +822,7 @@ void ICollection.CopyTo(Array array, int index)
                 {
                     if (entries[i].hashCode >= 0)
                     {
-                        dictEntryArray[index + i] = new DictionaryEntry(entries[i].key, entries[i].value);
+                        dictEntryArray[index++] = new DictionaryEntry(entries[i].key, entries[i].value);
                     }
                 }
             }
@@ -842,7 +842,7 @@ void ICollection.CopyTo(Array array, int index)
                     {
                         if (entries[i].hashCode >= 0)
                         {
-                            objects[index + i] = new KeyValuePair<TKey, TValue>(entries[i].key, entries[i].value);
+                            objects[index++] = new KeyValuePair<TKey, TValue>(entries[i].key, entries[i].value);
                         }
                     }
                 }
@@ -1210,7 +1210,7 @@ public void CopyTo(TKey[] array, int index)
                 Entry[] entries = _dictionary._entries;
                 for (int i = 0; i < count; i++)
                 {
-                    if (entries[i].hashCode >= 0) array[index + i] = entries[i].key;
+                    if (entries[i].hashCode >= 0) array[index++] = entries[i].key;
                 }
             }
 
@@ -1270,7 +1270,7 @@ void ICollection.CopyTo(Array array, int index)
                     {
                         for (int i = 0; i < count; i++)
                         {
-                            if (entries[i].hashCode >= 0) objects[index + i] = entries[i].key;
+                            if (entries[i].hashCode >= 0) objects[index++] = entries[i].key;
                         }
                     }
                     catch (ArrayTypeMismatchException)
@@ -1393,7 +1393,7 @@ public void CopyTo(TValue[] array, int index)
                 Entry[] entries = _dictionary._entries;
                 for (int i = 0; i < count; i++)
                 {
-                    if (entries[i].hashCode >= 0) array[index + i] = entries[i].value;
+                    if (entries[i].hashCode >= 0) array[index++] = entries[i].value;
                 }
             }
 
@@ -1453,7 +1453,7 @@ void ICollection.CopyTo(Array array, int index)
                     {
                         for (int i = 0; i < count; i++)
                         {
-                            if (entries[i].hashCode >= 0) objects[index + i] = entries[i].value;
+                            if (entries[i].hashCode >= 0) objects[index++] = entries[i].value;
                         }
                     }
                     catch (ArrayTypeMismatchException)
diff --git a/src/mscorlib/shared/System/Collections/Generic/List.cs b/src/mscorlib/shared/System/Collections/Generic/List.cs
index a5cbf12a658b..6b9f9b45b35c 100644
--- a/src/mscorlib/shared/System/Collections/Generic/List.cs
+++ b/src/mscorlib/shared/System/Collections/Generic/List.cs
@@ -163,12 +163,12 @@ public T this[int index]
 
             set
             {
-                _version++;
                 if ((uint)index >= (uint)_size)
                 {
                     ThrowHelper.ThrowArgumentOutOfRange_IndexException();
                 }
                 _items[index] = value;
+                _version++;
             }
         }