diff --git a/python-insert-docstring-tests.el b/python-insert-docstring-tests.el
index 05d9ced..f66d9fe 100644
--- a/python-insert-docstring-tests.el
+++ b/python-insert-docstring-tests.el
@@ -111,6 +111,8 @@
                     "  first: Type = 1,\n  second: Map[some, other] = 2") '("first" "second")))
     (should (equal (python-insert-docstring--get-arguments-names-from-string
                     "  first = 1,\n  second = 2") '("first" "second")))
+    (should (equal (python-insert-docstring--get-arguments-names-from-string
+                    "  cls ,\n  second = 2") '("second")))
     (should (equal (python-insert-docstring--get-arguments-names-from-string
                     "  self ,\n  second = 2") '("second")))))
 
diff --git a/python-insert-docstring.el b/python-insert-docstring.el
index a5b5efb..ad91f70 100644
--- a/python-insert-docstring.el
+++ b/python-insert-docstring.el
@@ -158,8 +158,7 @@
                                                      "Drop type data"
                                                      (car (split-string single-argument-string ":")))
                                                    (split-string arguments-string ","))))))
-      (if (string-equal (car arguments)
-                        "self")
+      (if (member (car arguments) '("self" "cls"))
           (cdr arguments)
         arguments))))