diff --git a/.gitignore b/.gitignore
index f590abc..25f903c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -34,3 +34,5 @@ compile_commands.json
 /docs/adoc/
 /build/
 /installtest/.build/
+
+.idea
diff --git a/include/beman/optional/detail/stl_interfaces/config.hpp b/include/beman/optional/detail/stl_interfaces/config.hpp
index 0d5a088..88dbb81 100644
--- a/include/beman/optional/detail/stl_interfaces/config.hpp
+++ b/include/beman/optional/detail/stl_interfaces/config.hpp
@@ -1,5 +1,4 @@
 // include/beman/optional/detail/stl_interfaces/config.hpp            -*-C++-*-
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
 // Copyright (C) 2020 T. Zachary Laine
 //
diff --git a/include/beman/optional/detail/stl_interfaces/fwd.hpp b/include/beman/optional/detail/stl_interfaces/fwd.hpp
index 08bc9ca..ffcfcca 100644
--- a/include/beman/optional/detail/stl_interfaces/fwd.hpp
+++ b/include/beman/optional/detail/stl_interfaces/fwd.hpp
@@ -1,5 +1,4 @@
 // include/beman/optional/detail/stl_interfaces/fwd.hpp               -*-C++-*-
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
 // Copyright (C) 2019 T. Zachary Laine
 //
diff --git a/include/beman/optional/detail/stl_interfaces/iterator_interface.hpp b/include/beman/optional/detail/stl_interfaces/iterator_interface.hpp
index 3c8c373..56272ce 100644
--- a/include/beman/optional/detail/stl_interfaces/iterator_interface.hpp
+++ b/include/beman/optional/detail/stl_interfaces/iterator_interface.hpp
@@ -1,5 +1,4 @@
 // include/beman/optional/detail/stl_interfaces/iterator_interface.hpp -*-C++-*-
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
 // Copyright (C) 2019 T. Zachary Laine
 //