diff --git a/Tools/px4airframes/srcscanner.py b/Tools/px4airframes/srcscanner.py
index cb31906a30..398c7ed067 100644
--- a/Tools/px4airframes/srcscanner.py
+++ b/Tools/px4airframes/srcscanner.py
@@ -16,9 +16,11 @@ class SourceScanner(object):
         extensions = tuple(parser.GetSupportedExtensions())
         for dirname, dirnames, filenames in os.walk(srcdir):
             for filename in filenames:
-                path = os.path.join(dirname, filename)
-                if not self.ScanFile(path, parser):
-                    return False
+                extension = os.path.splitext(filename)[1]
+                if extension in extensions:
+                    path = os.path.join(dirname, filename)
+                    if not self.ScanFile(path, parser):
+                        return False
         return True
 
     def ScanFile(self, path, parser):