diff --git a/tools/building.py b/tools/building.py
index 3c2dbc4e7498524181b4287f886513e59d25f9ff..83f034deb37066ba68390e9cedbe9078123db2c4 100644
--- a/tools/building.py
+++ b/tools/building.py
@@ -493,6 +493,9 @@ def EndBuilding(target, program = None):
         CscopeDatabase(Projects)
 
 def SrcRemove(src, remove):
+    if not src:
+        return
+
     if type(src[0]) == type('str'):
         for item in src:
             if os.path.basename(item) in remove: