diff --git a/lib/pbxFile.js b/lib/pbxFile.js
index 59dcef9..2ed90be 100644
--- a/lib/pbxFile.js
+++ b/lib/pbxFile.js
@@ -34,6 +34,7 @@ const FILETYPE_BY_EXTENSION = {
     framework: 'wrapper.framework',
     h: 'sourcecode.c.h',
     m: 'sourcecode.c.objc',
+    mm: 'sourcecode.cpp.objcpp',
     markdown: 'text',
     mdimporter: 'wrapper.cfbundle',
     octest: 'wrapper.cfbundle',
@@ -58,6 +59,7 @@ const GROUP_BY_FILETYPE = {
     'embedded.framework': 'Embed Frameworks',
     'sourcecode.c.h': 'Resources',
     'sourcecode.c.objc': 'Sources',
+    'sourcecode.cpp.objcpp': 'Sources',
     'sourcecode.swift': 'Sources'
 };
 const PATH_BY_FILETYPE = {
@@ -73,6 +75,7 @@ const SOURCETREE_BY_FILETYPE = {
 const ENCODING_BY_FILETYPE = {
     'sourcecode.c.h': 4,
     'sourcecode.c.objc': 4,
+    'sourcecode.cpp.objcpp': 4,
     'sourcecode.swift': 4,
     text: 4,
     'text.plist.xml': 4,
diff --git a/test/addSourceFile.js b/test/addSourceFile.js
index 409bad0..053fae7 100644
--- a/test/addSourceFile.js
+++ b/test/addSourceFile.js
@@ -162,4 +162,31 @@ describe('addSourceFile', () => {
         assert.strictEqual(plugins.children.length, 1);
         assert.strictEqual(sources.files.length, 3);
     });
+
+    it('should add objc source files and return pbxFile', () => {
+        const newFile = proj.addSourceFile('file.m');
+        assert.strictEqual(newFile.constructor, PBXFile);
+        assert.strictEqual(newFile.lastKnownFileType, 'sourcecode.c.objc');
+        assert.strictEqual(newFile.group, 'Sources');
+        assert.strictEqual(newFile.defaultEncoding, 4);
+        assert.strictEqual(newFile.fileEncoding, 4);
+    });
+
+    it('should add objc++ source files and return pbxFile', () => {
+        const newFile = proj.addSourceFile('file.mm');
+        assert.strictEqual(newFile.constructor, PBXFile);
+        assert.strictEqual(newFile.lastKnownFileType, 'sourcecode.cpp.objcpp');
+        assert.strictEqual(newFile.group, 'Sources');
+        assert.strictEqual(newFile.defaultEncoding, 4);
+        assert.strictEqual(newFile.fileEncoding, 4);
+    });
+
+    it('should add swift source files and return pbxFile', () => {
+        const newFile = proj.addSourceFile('file.swift');
+        assert.strictEqual(newFile.constructor, PBXFile);
+        assert.strictEqual(newFile.lastKnownFileType, 'sourcecode.swift');
+        assert.strictEqual(newFile.group, 'Sources');
+        assert.strictEqual(newFile.defaultEncoding, 4);
+        assert.strictEqual(newFile.fileEncoding, 4);
+    });
 });