diff --git a/tools/keil.py b/tools/keil.py
index 214b3928d4ed636d19626372a4418b6d5d066698..16fc0d1fc5ad5d74602f5c0073899796b1e57c13 100644
--- a/tools/keil.py
+++ b/tools/keil.py
@@ -221,9 +221,19 @@ def MDK5AddGroupForFN(ProjectFiles, parent, name, filename, project_path):
     file = SubElement(files, 'File')
     file_name = SubElement(file, 'FileName')
     name = os.path.basename(path)
-    if ProjectFiles.count(name):
+
+    if name.find('.cpp') != -1:
+        obj_name = name.replace('.cpp', '.o')
+    elif name.find('.c') != -1:
+        obj_name = name.replace('.c', '.o')
+    elif name.find('.s') != -1:
+        obj_name = name.replace('.s', '.o')
+    elif name.find('.S') != -1:
+        obj_name = name.replace('.s', '.o')
+
+    if ProjectFiles.count(obj_name):
         name = basename + '_' + name
-    ProjectFiles.append(name)
+    ProjectFiles.append(obj_name)
     file_name.text = name.decode(fs_encoding)
     file_type = SubElement(file, 'FileType')
     file_type.text = '%d' % _get_filetype(name)
@@ -253,9 +263,19 @@ def MDK5AddGroup(ProjectFiles, parent, name, files, project_path):
         file = SubElement(files, 'File')
         file_name = SubElement(file, 'FileName')
         name = os.path.basename(path)
-        if ProjectFiles.count(name):
+
+        if name.find('.cpp') != -1:
+            obj_name = name.replace('.cpp', '.o')
+        elif name.find('.c') != -1:
+            obj_name = name.replace('.c', '.o')
+        elif name.find('.s') != -1:
+            obj_name = name.replace('.s', '.o')
+        elif name.find('.S') != -1:
+            obj_name = name.replace('.s', '.o')
+
+        if ProjectFiles.count(obj_name):
             name = basename + '_' + name
-        ProjectFiles.append(name)
+        ProjectFiles.append(obj_name)
         file_name.text = name.decode(fs_encoding)
         file_type = SubElement(file, 'FileType')
         file_type.text = '%d' % _get_filetype(name)