diff --git a/CHANGES.current b/CHANGES.current
index 9ea6662cc..e31a71ab9 100644
--- a/CHANGES.current
+++ b/CHANGES.current
@@ -7,6 +7,9 @@ the issue number to the end of the URL: https://github.com/swig/swig/issues/
 Version 3.0.13 (in progress)
 ============================
 
+2017-04-20: wsfulton
+            [Ruby] #586, #935 Add assert for invalid NULL type parameter when calling SWIG_Ruby_NewPointerObj.
+
 2017-04-20: tamuratak
             [Ruby] #930, #937 - Fix containers of std::shared_ptr.
             Upcasting, const types (eg vector<shared_ptr<const T>>) and NULL/nullptr support added.
diff --git a/Lib/ruby/rubyrun.swg b/Lib/ruby/rubyrun.swg
index 94618db4e..4628aedc3 100644
--- a/Lib/ruby/rubyrun.swg
+++ b/Lib/ruby/rubyrun.swg
@@ -171,10 +171,11 @@ SWIG_Ruby_NewPointerObj(void *ptr, swig_type_info *type, int flags)
   swig_class *sklass;
   VALUE klass;
   VALUE obj;
-  
+
   if (!ptr)
     return Qnil;
-  
+
+  assert(type);
   if (type->clientdata) {
     sklass = (swig_class *) type->clientdata;
 		
@@ -182,7 +183,7 @@ SWIG_Ruby_NewPointerObj(void *ptr, swig_type_info *type, int flags)
     track = sklass->trackObjects;
     if (track) {
       obj = SWIG_RubyInstanceFor(ptr);
-      
+
       /* Check the object's type and make sure it has the correct type.
         It might not in cases where methods do things like 
         downcast methods. */
@@ -214,7 +215,7 @@ SWIG_Ruby_NewPointerObj(void *ptr, swig_type_info *type, int flags)
     obj = Data_Wrap_Struct(klass, 0, 0, ptr);
   }
   rb_iv_set(obj, "@__swigtype__", rb_str_new2(type->name));
-  
+
   return obj;
 }