diff --git a/features/mark-things.feature b/features/mark-things.feature
new file mode 100644
index 0000000..cfe880a
--- /dev/null
+++ b/features/mark-things.feature
@@ -0,0 +1,18 @@
+Feature: Mark things
+
+  Scenario: Mark symbols in defun with select
+    Given I turn on emacs-lisp-mode
+    And I turn on delete-selection-mode
+    And I insert:
+    """
+    (defun abc (ghi) (message ghi))
+    (defun def (ghi) (message some-other-ghi))
+    """
+    When I select "ghi"
+    And I mark all symbols like this in defun
+    And I type "hmm"
+    Then I should see:
+    """
+    (defun abc (hmm) (message hmm))
+    (defun def (ghi) (message some-other-ghi))
+    """
diff --git a/features/step-definitions/multiple-cursors-steps.el b/features/step-definitions/multiple-cursors-steps.el
index 900eeed..ba25181 100644
--- a/features/step-definitions/multiple-cursors-steps.el
+++ b/features/step-definitions/multiple-cursors-steps.el
@@ -95,3 +95,11 @@
           (assert search nil "The text '%s' was not found in the current buffer." text))
         (set-mark (point))
         (re-search-forward text)))
+
+(When "^I mark all \\(.+\\)$"
+      (lambda (rest)
+        (let ((func (intern (mapconcat 'identity
+                                       (cons  "mc/mark-all"
+                                              (split-string rest))
+                                       "-"))))
+          (call-interactively func))))