diff --git a/lib/Viewer.js b/lib/Viewer.js
index 07ba5b7f..0c691e34 100644
--- a/lib/Viewer.js
+++ b/lib/Viewer.js
@@ -22,7 +22,7 @@ var Diagram = require('diagram-js'),
 
 var inherits = require('inherits');
 
-var Importer = require('./import/Importer');
+var importBpmnDiagram = require('./import/Importer').importBpmnDiagram;
 
 
 function checkValidationError(err) {
@@ -292,6 +292,8 @@ Viewer.prototype.saveSVG = function(options, done) {
 
 Viewer.prototype.importDefinitions = function(definitions, done) {
 
+  var err;
+
   // use try/catch to not swallow synchronous exceptions
   // that may be raised during model parsing
   try {
@@ -305,12 +307,13 @@ Viewer.prototype.importDefinitions = function(definitions, done) {
     this._definitions = definitions;
 
     // perform graphical import
-    Importer.importBpmnDiagram(this, definitions, done);
+    return importBpmnDiagram(this, definitions, done);
   } catch (e) {
-
-    // handle synchronous errors
-    done(e);
+    err = e;
   }
+
+  // handle synchronous errors
+  return done(err);
 };
 
 Viewer.prototype.getModules = function() {