diff --git a/requirements.in b/requirements.in
index 3ae84a6..a3831ef 100644
--- a/requirements.in
+++ b/requirements.in
@@ -2,3 +2,6 @@ lxml
 rich
 validators
 dnspython
+inflect
+cogapp
+dbus-python
diff --git a/requirements.txt b/requirements.txt
index 799f80a..28fb98c 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,13 +4,19 @@
 #
 #    pip-compile
 #
+cogapp==3.3.0
+    # via -r requirements.in
 commonmark==0.9.1
     # via rich
+dbus-python==1.2.18
+    # via -r requirements.in
 decorator==5.1.1
     # via validators
 dnspython==2.2.1
     # via -r requirements.in
-lxml==4.9.0
+inflect==5.6.0
+    # via -r requirements.in
+lxml==4.9.1
     # via -r requirements.in
 pygments==2.12.0
     # via rich
diff --git a/update-firewall-source.py b/update-firewall-source.py
index d5cef6a..8f30ed3 100644
--- a/update-firewall-source.py
+++ b/update-firewall-source.py
@@ -16,6 +16,12 @@ import validators
 # Build XML structure
 import lxml.etree
 import lxml.builder
+# Correctly generate plurals, singular nouns etc.
+import inflect
+# Restart firewalld systemd service unit
+import dbus
+# Find physical network interface via 'find' command
+import subprocess
 
 
 # Exit codes