diff --git a/rwx/os/pm/__init__.py b/rwx/os/pm/__init__.py
index 6236ee6..c55179a 100644
--- a/rwx/os/pm/__init__.py
+++ b/rwx/os/pm/__init__.py
@@ -16,8 +16,14 @@ class PM(Class, ABC):
 
     @abstractmethod
     def get_clean_command(self) -> Command:
-        """Command to clean packages cache."""
+        """Command to clean packages cache.
+
+        :rtype: Command
+        """
 
     @abstractmethod
     def get_install_command(self) -> Command:
-        """Command to install package(s)."""
+        """Command to install package(s).
+
+        :rtype: Command
+        """
diff --git a/rwx/os/pm/apt.py b/rwx/os/pm/apt.py
index 03217b8..3e3cb81 100644
--- a/rwx/os/pm/apt.py
+++ b/rwx/os/pm/apt.py
@@ -8,9 +8,15 @@ class APT(PM):
     """Advanced Package Tool."""
 
     def get_clean_command(self) -> Command:
-        """Return clean command."""
+        """Return clean command.
+
+        :rtype: Command
+        """
         return Command()
 
     def get_install_command(self) -> Command:
-        """Return install command."""
+        """Return install command.
+
+        :rtype: Command
+        """
         return Command()