diff --git a/SConstruct b/SConstruct
index a460a0b43..241511fd1 100644
--- a/SConstruct
+++ b/SConstruct
@@ -813,7 +813,7 @@ class DXXProgram(DXXCommon):
 	}])
 	objects_editor = DXXCommon.create_lazy_object_property([{
 		'source':[os.path.join('similar', f) for f in [
-'editor/autosave.c',
+'editor/autosave.cpp',
 'editor/centers.c',
 'editor/curves.c',
 'editor/eglobal.c',
diff --git a/similar/editor/autosave.c b/similar/editor/autosave.cpp
similarity index 100%
rename from similar/editor/autosave.c
rename to similar/editor/autosave.cpp