Index: oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/nodetype/write/NodeTypeTemplateImpl.java
===================================================================
--- oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/nodetype/write/NodeTypeTemplateImpl.java	(revision 1733462)
+++ oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/nodetype/write/NodeTypeTemplateImpl.java	(working copy)
@@ -178,8 +178,20 @@
 
     private static void writeItemDefinitions(@Nonnull Tree nodeTypeTree, @CheckForNull List<? extends ItemDefinitionTemplate> itemDefTemplates,
                                              @Nonnull String nodeName, @Nonnull String primaryTypeName) throws RepositoryException {
+        // first remove potentially existing item definitions
+        removeChild(nodeTypeTree, nodeName);
+        // Oak versions prior to 1.4 wrote explicit one index (OAK-4085)
+        removeChild(nodeTypeTree, nodeName + "[1]");
+        // remove remaining if any
         Tree tree;
-        int index = 1;
+        int index = 2;
+        tree = nodeTypeTree.getChild(nodeName(nodeName, index++));
+        while (tree.exists()) {
+            tree.remove();
+            tree = nodeTypeTree.getChild(nodeName(nodeName, index++));
+        }
+        // now write definitions
+        index = 1;
         if (itemDefTemplates != null) {
             for (ItemDefinitionTemplate template : itemDefTemplates) {
                 String name = nodeName(nodeName, index);
@@ -193,10 +205,12 @@
                 index++;
             }
         }
-        tree = nodeTypeTree.getChild(nodeName(nodeName, index++));
-        while (tree.exists()) {
-            tree.remove();
-            tree = nodeTypeTree.getChild(nodeName(nodeName, index++));
+    }
+
+    private static void removeChild(Tree tree, String name) {
+        Tree child = tree.getChild(name);
+        if (child.exists()) {
+            child.remove();
         }
     }