diff --git a/tools/keil.py b/tools/keil.py
index 2b47a36169a08e87bb978cccc03693d0cbc170f1..7243898a08e9d101d32a377aac255ec223bff8e2 100644
--- a/tools/keil.py
+++ b/tools/keil.py
@@ -54,7 +54,11 @@ def MDK4AddGroup(ProjectFiles, parent, name, files, project_path):
 
 def MDK4Project(target, script):
     project_path = os.path.dirname(os.path.abspath(target))
-    
+
+    project_uvopt = os.path.abspath(target).replace('uvproj', 'uvopt')
+    if os.path.isfile(project_uvopt):
+        os.unlink(project_uvopt)
+
     tree = etree.parse('template.uvproj')
     root = tree.getroot()