@@ -31,7 +31,10 @@ Optional argument
 Optional argument with default
     Check Test Case    ${TESTNAME}
 
-Optional string with default
+Optional string with None default
+    Check Test Case    ${TESTNAME}
+
+String with None default
     Check Test Case    ${TESTNAME}
 
 Avoid unnecessary conversion
 
@@ -55,7 +55,11 @@ def optional_argument_with_default(argument: Optional[float] = None, expected=ob
     assert argument == expected
 
 
-def optional_string_with_default(argument: Optional[str] = None, expected=object()):
+def optional_string_with_none_default(argument: Optional[str] = None, expected=object()):
+    assert argument == expected
+
+
+def string_with_none_default(argument: str = None, expected=object()):
     assert argument == expected
 
 
 
@@ -72,8 +72,17 @@ Optional argument with default
     ${None}    ${None}
     expected=${None}
 
-Optional string with default
-    [Template]    Optional string with default
+Optional string with None default
+    [Template]    Optional string with None default
+    Hyvä!      Hyvä!
+    1          1
+    ${1}       1
+    None       None
+    ${None}    ${None}
+    expected=${None}
+
+String with None default
+    [Template]    String with None default
     Hyvä!      Hyvä!
     1          1
     ${1}       1