diff --git a/plantuml-mode.el b/plantuml-mode.el
index 6072e3e..b3041ba 100644
--- a/plantuml-mode.el
+++ b/plantuml-mode.el
@@ -343,7 +343,7 @@ Uses prefix (as PREFIX) to choose where to display it:
     (defvar plantuml-keywords-regexp (concat "^\\s *" (regexp-opt plantuml-keywords 'words)  "\\|\\(<\\|<|\\|\\*\\|o\\)\\(\\.+\\|-+\\)\\|\\(\\.+\\|-+\\)\\(>\\||>\\|\\*\\|o\\)\\|\\.\\{2,\\}\\|-\\{2,\\}"))
     (defvar plantuml-builtins-regexp (regexp-opt plantuml-builtins 'words))
     (defvar plantuml-preprocessors-regexp (concat "^\\s *" (regexp-opt plantuml-preprocessors 'words)))
-    (defvar plantuml-indent-regexp-start "^[ \t]*\\(\\(?:.*\\)?\s*\\(?:[<>.*a-z-|]+\\)?\s*\\(?:\\[[a-zA-Z]+\\]\\)?\s+if\\|loop\s+.*\\|group\s+.*\\|par\s+\\|opt\s+.*\\|alt\s+.*\\|else\s+.*\\|note\s+over\\|note\sas\s.*\\|note\s+\\(\\(?:\\(?:buttom\\|left\\|right\\|top\\)\\)\\)\\(?:\s+of\\)?\\|\\(?:class\\|enum\\|package\\)\s+.*{\\|activate\s+.*\\)")
+    (defvar plantuml-indent-regexp-start "^[ \t]*\\(\\(?:.*\\)?\s*\\(?:[<>.*a-z-|]+\\)?\s*\\(?:\\[[a-zA-Z]+\\]\\)?\s+if\s+.*\\|loop\s+.*\\|group\s+.*\\|par\s+\\|opt\s+.*\\|alt\s+.*\\|else\\|note\s+over\\|note\sas\s.*\\|note\s+\\(\\(?:\\(?:buttom\\|left\\|right\\|top\\)\\)\\)\\(?:\s+of\\)?\\|\\(?:class\\|enum\\|package\\)\s+.*{\\|activate\s+.*\\)")
     (defvar plantuml-indent-regexp-end "^[ \t]*\\(endif\\|else\\|end\\|end\s+note\\|.*}\\|deactivate\s+.*\\)")
 
     (setq plantuml-font-lock-keywords
diff --git a/test/plantuml-indentation-test.el b/test/plantuml-indentation-test.el
index c8bc723..110922e 100644
--- a/test/plantuml-indentation-test.el
+++ b/test/plantuml-indentation-test.el
@@ -194,17 +194,22 @@ else
 |end
 ")
 
-(check-indentation alt-else-body
-  "alt choice 1
-else
-|A -> B
-end
-"
-  "alt choice 1
-else
-  |A -> B
-end
-")
+(check-indentation opt
+  "opt have fun
+|some text
+end"
+  "opt have fun
+  |some text
+end")
+
+(check-indentation activate-deactivate
+  "activate participant_1
+|participant_1 -> participant_2 : f()
+deactivate participant_1"
+  "activate participant_1
+  |participant_1 -> participant_2 : f()
+deactivate participant_1")
+
 
 (provide 'plantuml-indentation-test)