diff --git a/debian/apertis/copyright b/debian/apertis/copyright
index 20b0414c20491310016731091ca82fa6f719863b..db5036f47bcb30e7b9b90a9d1acdc51fa0172772 100644
--- a/debian/apertis/copyright
+++ b/debian/apertis/copyright
@@ -18,7 +18,7 @@ License: GPL-3+ with Autoconf-2.0~Archive exception
 
 Files: m4/ax_pthread.m4
 Copyright: no-info-found
-License: GPL
+License: GPL-3+ with Autoconf-exception-3.0
 
 Files: m4/ax_tls.m4
 Copyright: no-info-found