diff --git a/templates/docs/_data/plugins.py b/templates/docs/_data/plugins.py
index cbac0510eaaef2f22dcce4593f6c701b341d8066..223f3031d8840058d11afa583ae7fc311c05a88e 100644
--- a/templates/docs/_data/plugins.py
+++ b/templates/docs/_data/plugins.py
@@ -914,9 +914,11 @@ def define_env(env: dict) -> None:
             var: Key in env.variables to return.
 
         Returns:
-            The value of `env.variables[var]`.
+            The value of `env.variables[var]` if it exists, else return None.
         """
-        return env.variables[var]
+        if var in env.variables:
+            return env.variables[var]
+        return None
 
     @env.macro
     # pylint: disable=W0612