diff --git a/rhino/src/main/java/org/mozilla/javascript/ScriptRuntime.java b/rhino/src/main/java/org/mozilla/javascript/ScriptRuntime.java
index 4f7c2fb09c..9edefaf67d 100644
--- a/rhino/src/main/java/org/mozilla/javascript/ScriptRuntime.java
+++ b/rhino/src/main/java/org/mozilla/javascript/ScriptRuntime.java
@@ -188,7 +188,7 @@ public static ScriptableObject initSafeStandardObjects(
 
         NativeArrayIterator.init(scope, sealed);
         NativeStringIterator.init(scope, sealed);
-        getRegExpProxy(cx).register(scope, sealed);
+        registerRegExp(cx, scope, sealed);
 
         NativeJavaObject.init(scope, sealed);
         NativeJavaMap.init(scope, sealed);
@@ -298,6 +298,13 @@ public static ScriptableObject initSafeStandardObjects(
         return scope;
     }
 
+    private static void registerRegExp(Context cx, ScriptableObject scope, boolean sealed) {
+        RegExpProxy regExpProxy = getRegExpProxy(cx);
+        if (regExpProxy != null) {
+            regExpProxy.register(scope, sealed);
+        }
+    }
+
     public static ScriptableObject initStandardObjects(
             Context cx, ScriptableObject scope, boolean sealed) {
         ScriptableObject s = initSafeStandardObjects(cx, scope, sealed);
diff --git a/rhino/src/main/java/org/mozilla/javascript/regexp/NativeRegExpStringIterator.java b/rhino/src/main/java/org/mozilla/javascript/regexp/NativeRegExpStringIterator.java
index 46454cec2b..1974040952 100644
--- a/rhino/src/main/java/org/mozilla/javascript/regexp/NativeRegExpStringIterator.java
+++ b/rhino/src/main/java/org/mozilla/javascript/regexp/NativeRegExpStringIterator.java
@@ -19,6 +19,13 @@ public final class NativeRegExpStringIterator extends ES6Iterator {
     private static final long serialVersionUID = 1L;
     private static final String ITERATOR_TAG = "RegExpStringIterator";
 
+    private Scriptable regexp;
+    private String string;
+    private boolean global;
+    private boolean fullUnicode;
+    private boolean nextDone;
+    private Object next = null;
+
     public static void init(ScriptableObject scope, boolean sealed) {
         ES6Iterator.init(scope, sealed, new NativeRegExpStringIterator(), ITERATOR_TAG);
     }
@@ -101,11 +108,4 @@ private Object regExpExec(Context cx, Scriptable scope) {
     protected String getTag() {
         return ITERATOR_TAG;
     }
-
-    private Scriptable regexp;
-    private String string;
-    private boolean global;
-    private boolean fullUnicode;
-    private boolean nextDone;
-    private Object next = null;
 }