diff --git a/src/actors/mod.rs b/src/actors/mod.rs
index 8e45d673..fe23d468 100644
--- a/src/actors/mod.rs
+++ b/src/actors/mod.rs
@@ -1,5 +1,5 @@
 /* Copyright (C) 2022 Purism SPC
- * SPDX-License-Identifier: GPL-3.0+
+ * SPDX-License-Identifier: GPL-3.0-or-later
  */
 
 /*! Actors are parts of Squeekboard containing state independent from the main application state.
diff --git a/src/actors/popover.rs b/src/actors/popover.rs
index c2a3caa2..8bbca70d 100644
--- a/src/actors/popover.rs
+++ b/src/actors/popover.rs
@@ -1,5 +1,5 @@
 /* Copyright (C) 2022 Purism SPC
- * SPDX-License-Identifier: GPL-3.0+
+ * SPDX-License-Identifier: GPL-3.0-or-later
  */
 
 /*! The popover is opened directly by the GTK surface,
diff --git a/src/animation.rs b/src/animation.rs
index f1c53fd0..61b6c3f2 100644
--- a/src/animation.rs
+++ b/src/animation.rs
@@ -1,5 +1,5 @@
 /* Copyright (C) 2020 Purism SPC
- * SPDX-License-Identifier: GPL-3.0+
+ * SPDX-License-Identifier: GPL-3.0-or-later
  */
 
 /*! Animation details */
diff --git a/src/data/loading.rs b/src/data/loading.rs
index c3c26853..c26108df 100644
--- a/src/data/loading.rs
+++ b/src/data/loading.rs
@@ -1,5 +1,5 @@
 /* Copyright (C) 2020-2021 Purism SPC
- * SPDX-License-Identifier: GPL-3.0+
+ * SPDX-License-Identifier: GPL-3.0-or-later
  */
 
 /*! Loading layout files */
diff --git a/src/data/mod.rs b/src/data/mod.rs
index 99c7660b..cc85662e 100644
--- a/src/data/mod.rs
+++ b/src/data/mod.rs
@@ -1,5 +1,5 @@
 /* Copyright (C) 2020-2021 Purism SPC
- * SPDX-License-Identifier: GPL-3.0+
+ * SPDX-License-Identifier: GPL-3.0-or-later
  */
 
 /*! Combined module for dealing with layout files */
diff --git a/src/data/parsing.rs b/src/data/parsing.rs
index b70a2ffe..2525e1ae 100644
--- a/src/data/parsing.rs
+++ b/src/data/parsing.rs
@@ -1,5 +1,5 @@
 /* Copyright (C) 2020-2021 Purism SPC
- * SPDX-License-Identifier: GPL-3.0+
+ * SPDX-License-Identifier: GPL-3.0-or-later
  */
 
 /*! Parsing of the data files containing layouts */
diff --git a/src/event_loop/driver.rs b/src/event_loop/driver.rs
index 4fb57ff0..b29b5a5d 100644
--- a/src/event_loop/driver.rs
+++ b/src/event_loop/driver.rs
@@ -1,5 +1,5 @@
 /* Copyright (C) 2021 Purism SPC
- * SPDX-License-Identifier: GPL-3.0+
+ * SPDX-License-Identifier: GPL-3.0-or-later
  */
  
 /*! This drives the loop from the `loop` module.
diff --git a/src/event_loop/mod.rs b/src/event_loop/mod.rs
index 05af69a7..1fde38b9 100644
--- a/src/event_loop/mod.rs
+++ b/src/event_loop/mod.rs
@@ -1,5 +1,5 @@
 /* Copyright (C) 2021 Purism SPC
- * SPDX-License-Identifier: GPL-3.0+
+ * SPDX-License-Identifier: GPL-3.0-or-later
  */
 
 /*! The loop abstraction for driving state changes.
diff --git a/src/main.rs b/src/main.rs
index e6360bfa..d410c18a 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,5 +1,5 @@
 /* Copyright (C) 2020,2022 Purism SPC
- * SPDX-License-Identifier: GPL-3.0+
+ * SPDX-License-Identifier: GPL-3.0-or-later
  */
 
 /*! Glue for the main loop. */
diff --git a/src/outputs.rs b/src/outputs.rs
index cbe7825c..ad9adcb9 100644
--- a/src/outputs.rs
+++ b/src/outputs.rs
@@ -1,5 +1,5 @@
 /* Copyright (C) 2019-2022 Purism SPC
- * SPDX-License-Identifier: GPL-3.0+
+ * SPDX-License-Identifier: GPL-3.0-or-later
  */
 
 /*! Managing Wayland outputs */
diff --git a/src/panel.rs b/src/panel.rs
index 5443f4b1..4691b0c2 100644
--- a/src/panel.rs
+++ b/src/panel.rs
@@ -1,5 +1,5 @@
 /* Copyright (C) 2022 Purism SPC
- * SPDX-License-Identifier: GPL-3.0+
+ * SPDX-License-Identifier: GPL-3.0-or-later
  */
 
 /*! Panel state management.
@@ -380,4 +380,4 @@ mod tests {
             },
         );
     }
-}
\ No newline at end of file
+}
diff --git a/src/server-main.c b/src/server-main.c
index a823f546..8b3dc212 100644
--- a/src/server-main.c
+++ b/src/server-main.c
@@ -2,7 +2,7 @@
  * Copyright (C) 2010-2011 Daiki Ueno <ueno@unixuser.org>
  * Copyright (C) 2010-2011 Red Hat, Inc.
  * Copyright (C) 2018-2019 Purism SPC
- * SPDX-License-Identifier: GPL-3.0+
+ * SPDX-License-Identifier: GPL-3.0-or-later
  * Author: Guido Günther <agx@sigxcpu.org>
  *
  * This program is free software: you can redistribute it and/or modify
diff --git a/src/state.rs b/src/state.rs
index 4998b29b..b4fea9fc 100644
--- a/src/state.rs
+++ b/src/state.rs
@@ -1,5 +1,5 @@
 /* Copyright (C) 2021,2022 Purism SPC
- * SPDX-License-Identifier: GPL-3.0+
+ * SPDX-License-Identifier: GPL-3.0-or-later
  */
 
 /*! Application-wide state is stored here.