diff --git a/lib/filterx/expr-plus.c b/lib/filterx/expr-plus.c
index dfcab844b7..9f66b0688e 100644
--- a/lib/filterx/expr-plus.c
+++ b/lib/filterx/expr-plus.c
@@ -1,3 +1,25 @@
+/*
+ * Copyright (c) 2024 Balazs Scheidler <balazs.scheidler@axoflow.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * As an additional exemption you are allowed to compile & link against the
+ * OpenSSL libraries as published by the OpenSSL project. See the file
+ * COPYING for details.
+ *
+ */
 #include "expr-plus.h"
 #include "object-string.h"
 #include "filterx-eval.h"
diff --git a/lib/filterx/expr-plus.h b/lib/filterx/expr-plus.h
index acb51c4a99..2a10e8117f 100644
--- a/lib/filterx/expr-plus.h
+++ b/lib/filterx/expr-plus.h
@@ -1,3 +1,25 @@
+/*
+ * Copyright (c) 2024 Balazs Scheidler <balazs.scheidler@axoflow.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * As an additional exemption you are allowed to compile & link against the
+ * OpenSSL libraries as published by the OpenSSL project. See the file
+ * COPYING for details.
+ *
+ */
 #ifndef FILTERX_EXPR_PLUS_H_INCLUDED
 #define FILTERX_EXPR_PLUS_H_INCLUDED