diff --git a/.gitignore b/.gitignore
index 8fa39a63..70f48d19 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,6 +16,7 @@
 npm-debug.log*
 yarn-error.log
 testem.log
+.idea
 
 # ember-try
 .node_modules.ember-try/
diff --git a/addon/system/drag-listener.js b/addon/system/drag-listener.js
index 53d0d078..27a518f9 100644
--- a/addon/system/drag-listener.js
+++ b/addon/system/drag-listener.js
@@ -91,15 +91,15 @@ export default class {
 
   getEventSource(evt) {
     let types = evt.dataTransfer.types || [];
-    let areAllTypesFiles = true;
+    let areSomeTypesFiles = false;
     for (let i = 0, len = types.length; i < len; i++) {
-      if (types[i] !== 'Files' &&
-          types[i] !== 'application/x-moz-file') {
-        areAllTypesFiles = false;
+      if (types[i] === 'Files' ||
+          types[i] === 'application/x-moz-file') {
+        areSomeTypesFiles = true;
         break;
       }
     }
-    return areAllTypesFiles ? 'os' : 'web';
+    return areSomeTypesFiles ? 'os' : 'web';
   }
 
   dragenter(evt) {