diff --git a/chrome/content/zotero/xpcom/attachments.js b/chrome/content/zotero/xpcom/attachments.js
index b480457e5a..81bb0da4a7 100644
--- a/chrome/content/zotero/xpcom/attachments.js
+++ b/chrome/content/zotero/xpcom/attachments.js
@@ -1128,9 +1128,9 @@ Zotero.Attachments = new function(){
 		
 		// Copy over files if they exist
 		if (newAttachment.isImportedAttachment() && attachment.getFile()) {
-			var dir = Zotero.Attachments.getStorageDirectory(attachment);
-			var newDir = yield Zotero.Attachments.createDirectoryForItem(newAttachment);
-			Zotero.File.copyDirectory(dir, newDir);
+			let dir = Zotero.Attachments.getStorageDirectory(attachment);
+			let newDir = yield Zotero.Attachments.createDirectoryForItem(newAttachment);
+			yield Zotero.File.copyDirectory(dir, newDir);
 		}
 		
 		yield newAttachment.addLinkedItem(attachment);
diff --git a/chrome/content/zotero/xpcom/file.js b/chrome/content/zotero/xpcom/file.js
index 413ae8e35f..b181698cb9 100644
--- a/chrome/content/zotero/xpcom/file.js
+++ b/chrome/content/zotero/xpcom/file.js
@@ -583,18 +583,26 @@ Zotero.File = new function(){
 	
 	/**
 	 * Copies all files from dir into newDir
+	 *
+	 * @param {String|nsIFile} source - Source directory
+	 * @param {String|nsIFile} target - Target directory
 	 */
-	this.copyDirectory = function (dir, newDir) {
-		if (!dir.exists()) {
-			throw ("Directory doesn't exist in Zotero.File.copyDirectory()");
-		}
-		var otherFiles = dir.directoryEntries;
-		while (otherFiles.hasMoreElements()) {
-			var file = otherFiles.getNext();
-			file.QueryInterface(Components.interfaces.nsIFile);
-			file.copyTo(newDir, null);
-		}
-	}
+	this.copyDirectory = Zotero.Promise.coroutine(function* (source, target) {
+		if (source instanceof Ci.nsIFile) source = source.path;
+		if (target instanceof Ci.nsIFile) target = target.path;
+		
+		yield OS.File.makeDir(target, {
+			ignoreExisting: true,
+			unixMode: 0o755
+		});
+		
+		return this.iterateDirectory(source, function* (iterator) {
+			while (true) {
+				let entry = yield iterator.next();
+				yield OS.File.copy(entry.path, OS.Path.join(target, entry.name));
+			}
+		})
+	});
 	
 	
 	this.createDirectoryIfMissing = function (dir) {
diff --git a/test/tests/fileTest.js b/test/tests/fileTest.js
new file mode 100644
index 0000000000..babf4509f5
--- /dev/null
+++ b/test/tests/fileTest.js
@@ -0,0 +1,31 @@
+describe("Zotero.File", function () {
+	describe("#copyDirectory()", function () {
+		it("should copy all files within a directory", function* () {
+			var tmpDir = Zotero.getTempDirectory().path;
+			var tmpCopyDir = OS.Path.join(tmpDir, "copyDirectory")
+			var source = OS.Path.join(tmpCopyDir, "1");
+			var target = OS.Path.join(tmpCopyDir, "2");
+			yield OS.File.makeDir(source, {
+				from: tmpDir
+			});
+			
+			yield Zotero.File.putContentsAsync(OS.Path.join(source, "A"), "Test 1");
+			yield Zotero.File.putContentsAsync(OS.Path.join(source, "B"), "Test 2");
+			
+			yield OS.File.removeDir(target, {
+				ignoreAbsent: true
+			});
+			
+			yield Zotero.File.copyDirectory(source, target);
+			
+			assert.equal(
+				(yield Zotero.File.getContentsAsync(OS.Path.join(target, "A"))),
+				"Test 1"
+			);
+			assert.equal(
+				(yield Zotero.File.getContentsAsync(OS.Path.join(target, "B"))),
+				"Test 2"
+			);
+		})
+	})
+})