diff --git a/chrome/content/zotero/xpcom/attachments.js b/chrome/content/zotero/xpcom/attachments.js
index 0e10a7465..b5909b609 100644
--- a/chrome/content/zotero/xpcom/attachments.js
+++ b/chrome/content/zotero/xpcom/attachments.js
@@ -82,14 +82,15 @@ Zotero.Attachments = new function(){
 			
 			// Create directory for attachment files within storage directory
 			var destDir = this.createDirectoryForItem(itemID);
-			file.copyTo(destDir, newName);
 			
 			// Point to copied file
 			var newFile = destDir.clone();
 			newFile.append(newName);
 			
-			var mimeType = Zotero.MIME.getMIMETypeFromFile(newFile);
+			// Copy file to unique filename, which automatically shortens long filenames
+			newFile = Zotero.File.copyToUnique(file, newFile);
 			
+			var mimeType = Zotero.MIME.getMIMETypeFromFile(newFile);
 			
 			attachmentItem.attachmentMIMEType = mimeType;
 			attachmentItem.attachmentPath = this.getPath(newFile, this.LINK_MODE_IMPORTED_FILE);
diff --git a/chrome/content/zotero/xpcom/file.js b/chrome/content/zotero/xpcom/file.js
index 7383d4572..3e98deef5 100644
--- a/chrome/content/zotero/xpcom/file.js
+++ b/chrome/content/zotero/xpcom/file.js
@@ -39,7 +39,6 @@ Zotero.File = new function(){
 	this.putContents = putContents;
 	this.getValidFileName = getValidFileName;
 	this.truncateFileName = truncateFileName;
-	this.copyToUnique = this.copyToUnique;
 	this.getCharsetFromFile = getCharsetFromFile;
 	this.addCharsetListener = addCharsetListener;
 	
@@ -287,14 +286,14 @@ Zotero.File = new function(){
 	}
 	
 	
-	function copyToUnique(file, newFile) {
+	this.copyToUnique = function (file, newFile) {
 		newFile.createUnique(Components.interfaces.nsIFile.NORMAL_FILE_TYPE, 0644);
 		var newName = newFile.leafName;
 		newFile.remove(null);
 		
 		// Copy file to unique name
 		file.copyTo(newFile.parent, newName);
-		return file;
+		return newFile;
 	}