diff --git a/js/checkNamespaces.js b/js/checkNamespaces.js
index 7e952627..009c6881 100644
--- a/js/checkNamespaces.js
+++ b/js/checkNamespaces.js
@@ -13,6 +13,7 @@ define( function() {
   'use strict';
 
   return function() {
+
     // Skip everything if we don't have assertions on, since that's the point of this function.
     if ( !assert ) {
       return;
@@ -22,41 +23,61 @@ define( function() {
     // information yet in the optimizer (with almond) and with require.js, so we have a fall-back set up.
     var defined = window.requirejs._defined || window.require.s.contexts._.defined;
 
-    for ( var moduleName in defined ) {
-      // Skip strings, images, or anything imported with a plugin. Could be added later if needed
-      if ( moduleName.indexOf( '!' ) >= 0 ) {
-        continue;
-      }
+    /**
+     * This function iterates over all defined AMD modules and reports to a problemHandler any problems.
+     * @param {function} problemHandler, a function that is called when an error occurs, with an {string} argument that
+     * describes the problem
+     */
+    var visit = function( problemHandler ) {
+      for ( var moduleName in defined ) {
+        // Skip strings, images, or anything imported with a plugin. Could be added later if needed
+        if ( moduleName.indexOf( '!' ) >= 0 ) {
+          continue;
+        }
 
-      // Skip anything without a slash (the plugins themselves, and the main/config files)
-      if ( moduleName.indexOf( '/' ) < 0 ) {
-        continue;
-      }
+        // Skip anything without a slash (the plugins themselves, and the main/config files)
+        if ( moduleName.indexOf( '/' ) < 0 ) {
+          continue;
+        }
 
-      // Skip anything with '..' in the path (chipper imports some things where we can't get the repository prefix)
-      if ( moduleName.indexOf( '..' ) >= 0 ) {
-        continue;
-      }
+        // Skip anything with '..' in the path (chipper imports some things where we can't get the repository prefix)
+        if ( moduleName.indexOf( '..' ) >= 0 ) {
+          continue;
+        }
 
-      var prefix = moduleName.slice( 0, moduleName.indexOf( '/' ) ); // e.g. 'SCENERY_PHET'
-      var name = moduleName.slice( moduleName.lastIndexOf( '/' ) + 1 ); // e.g. 'ArrowButton'
+        var prefix = moduleName.slice( 0, moduleName.indexOf( '/' ) ); // e.g. 'SCENERY_PHET'
+        var name = moduleName.slice( moduleName.lastIndexOf( '/' ) + 1 ); // e.g. 'ArrowButton'
 
-      // Convert to camel-case, e.g. 'SCENERY_PHET' to 'sceneryPhet'
-      var prefixTokens = prefix.toLowerCase().split( '_' );
-      var namespace = [ prefixTokens[ 0 ] ].concat( prefixTokens.slice( 1 ).map( function( token ) {
-        return token.charAt( 0 ).toUpperCase() + token.slice( 1 );
-      } ) ).join( '' );
+        // Convert to camel-case, e.g. 'SCENERY_PHET' to 'sceneryPhet'
+        var prefixTokens = prefix.toLowerCase().split( '_' );
+        var namespace = [ prefixTokens[ 0 ] ].concat( prefixTokens.slice( 1 ).map( function( token ) {
+          return token.charAt( 0 ).toUpperCase() + token.slice( 1 );
+        } ) ).join( '' );
 
-      // Skip things with the same name as the namespace, as this is most likely a namespace object (e.g. scenery.js)
-      if ( namespace === name ) {
-        continue;
+        // Skip things with the same name as the namespace, as this is most likely a namespace object (e.g. scenery.js)
+        if ( namespace === name ) {
+          continue;
+        }
+
+        var namespacedObject = phet[ namespace ] && phet[ namespace ][ name ];
+
+        if ( !namespacedObject ) {
+          problemHandler( 'not namespaced: ' + namespace + '.' + name );
+        }
+        if ( namespacedObject && namespacedObject !== defined[ moduleName ] ) {
+          problemHandler( namespace + '.' + name + ' is different than the expected namespaced object' );
+        }
       }
+    };
 
-      var namespacedObject = phet[ namespace ] && phet[ namespace ][ name ];
+    // First pass prints out all issues, to assist developers as we are adding the namespace register calls
+    visit( function( errorMessage ) {
+      console.log( errorMessage );
+    } );
 
-      assert && assert( namespacedObject, 'not namespaced: ' + namespace + '.' + name );
-      assert && assert( namespacedObject === defined[ moduleName ],
-        namespace + '.' + name + ' is different than the expected namespaced object' );
-    }
+    // Second pass fails with an assertion error.
+    visit( function( errorMessage ) {
+      assert && assert( false, errorMessage );
+    } );
   };
 } );