diff --git a/bin/cloudnet/tosca/tosca_diagrams.py b/bin/cloudnet/tosca/tosca_diagrams.py
index 8779c35..1dcdc50 100644
--- a/bin/cloudnet/tosca/tosca_diagrams.py
+++ b/bin/cloudnet/tosca/tosca_diagrams.py
@@ -2,7 +2,7 @@
 #
 # Software Name : Cloudnet TOSCA toolbox
 # Version: 1.0
-# SPDX-FileCopyrightText: Copyright (c) 2020-22 Orange
+# SPDX-FileCopyrightText: Copyright (c) 2020-24 Orange
 # SPDX-License-Identifier: Apache-2.0
 #
 # This software is distributed under the Apache License 2.0
@@ -185,7 +185,7 @@ def generation(self):
                 node_name,
                 ": ",
                 short_type_name(node_type),
-                '|\l\l\l\l" shape=record style=rounded]',
+                '|\\l\\l\\l\\l" shape=record style=rounded]',
                 sep="",
             )
             for capability_name, capability_yaml in syntax.get_capabilities(
diff --git a/bin/cloudnet/tosca/type_system.py b/bin/cloudnet/tosca/type_system.py
index 8e51002..532c750 100644
--- a/bin/cloudnet/tosca/type_system.py
+++ b/bin/cloudnet/tosca/type_system.py
@@ -2,7 +2,7 @@
 #
 # Software Name : Cloudnet TOSCA toolbox
 # Version: 1.0
-# SPDX-FileCopyrightText: Copyright (c) 2020-22 Orange
+# SPDX-FileCopyrightText: Copyright (c) 2020-24 Orange
 # SPDX-License-Identifier: Apache-2.0
 #
 # This software is distributed under the Apache License 2.0
@@ -346,7 +346,7 @@ def array_to_string_with_or_separator(a_list):
     return str(a_list).replace("['", "").replace("']", "").replace("', '", " or ")
 
 
-SCALAR_UNIT_RE = re.compile("^([0-9]+(\.[0-9]+)?)( )*([A-Za-z]+)$")
+SCALAR_UNIT_RE = re.compile("^([0-9]+(\\.[0-9]+)?)( )*([A-Za-z]+)$")
 
 
 def split_scalar_unit(a_string, units):
@@ -380,7 +380,7 @@ def normalize_scalar_unit(a_string, units):
     return scalar * units.get(unit)
 
 
-VERSION_RE = re.compile("^([0-9]+)\.([0-9]+)(((\.[0-9]+)?)(\.[A-Za-z]+(\-[0-9]+)?)?)?$")
+VERSION_RE = re.compile("^([0-9]+)\\.([0-9]+)(((\\.[0-9]+)?)(\\.[A-Za-z]+(\\-[0-9]+)?)?)?$")
 
 
 def check_version(a_string):
diff --git a/bin/cloudnet/tosca/utils.py b/bin/cloudnet/tosca/utils.py
index 1e2beb9..cad0316 100644
--- a/bin/cloudnet/tosca/utils.py
+++ b/bin/cloudnet/tosca/utils.py
@@ -2,7 +2,7 @@
 #
 # Software Name : Cloudnet TOSCA toolbox
 # Version: 1.0
-# SPDX-FileCopyrightText: Copyright (c) 2020 Orange
+# SPDX-FileCopyrightText: Copyright (c) 2020-24 Orange
 # SPDX-License-Identifier: Apache-2.0
 #
 # This software is distributed under the Apache License 2.0
@@ -15,7 +15,7 @@
 
 import re
 
-SCALAR_UNIT_RE = re.compile("^([0-9]+(\.[0-9]+)?)( )*([A-Za-z]+)$")
+SCALAR_UNIT_RE = re.compile("^([0-9]+(\\.[0-9]+)?)( )*([A-Za-z]+)$")
 
 
 def split_scalar_unit(scalar):