diff --git a/cfig/tests/test_config.py b/cfig/tests/test_config.py
index 60af0e3..5e990a8 100644
--- a/cfig/tests/test_config.py
+++ b/cfig/tests/test_config.py
@@ -58,7 +58,7 @@ class TestConfig:
             """The first number to sum."""
             try:
                 return int(val)
-            except ValueError:
+            except (ValueError, TypeError):
                 raise cfig.InvalidValueError("Not an int.")
 
         @basic_config.optional()
@@ -66,7 +66,7 @@ class TestConfig:
             """The second number to sum."""
             try:
                 return int(val)
-            except ValueError:
+            except (ValueError, TypeError):
                 raise cfig.InvalidValueError("Not an int.")
 
         yield basic_config
diff --git a/docs/quickstart.rst b/docs/quickstart.rst
index 7895deb..26bc70b 100644
--- a/docs/quickstart.rst
+++ b/docs/quickstart.rst
@@ -125,7 +125,7 @@ This allows us to perform some expensive operations inside, such as connecting t
         """The maximum number of users that will be able to login to this application."""
         try:
             return int(val)
-        except ValueError:
+        except (ValueError, TypeError):
             raise cfig.InvalidValueError("Not an int.")
 
 We can see that the new ``MAX_USERS`` configurable value processes the input string by trying to cast it into an :class:`int`, and raises a :exc:`~cfig.errors.InvalidValueError` containing the error message to display to the user if the cast fails.
@@ -168,7 +168,7 @@ To facilitate configuration on the users' part, :mod:`cfig` provides an integrat
         """The maximum number of users that will be able to login to this application."""
         try:
             return int(val)
-        except ValueError:
+        except (ValueError, TypeError):
             raise cfig.InvalidValueError("Not an int.")
 
     if __name__ == "__main__":