diff --git a/test/plantuml-indentation-basics-test.el b/test/plantuml-indentation-basics-test.el
index dad921e..23b9e43 100644
--- a/test/plantuml-indentation-basics-test.el
+++ b/test/plantuml-indentation-basics-test.el
@@ -258,332 +258,6 @@ foofoo|"
 
 
 
-
-
-
-(ert-deftest plantuml-test-block-indentation/package-empty ()
-  "Test correct indentation of an empty package block."
-  (plantuml-test-indent-block
-   "
-package APackage ()
-"
-   "
-package APackage ()
-"))
-
-
-(ert-deftest platuml-test-block-indentation/box ()
-  "Test correct indentation of a box block"
-  (plantuml-test-indent-block
-   "
-box \"Device with USB connector\"
-actor Human
-participant UsbDetector
-end box
-"
-   "
-box \"Device with USB connector\"
-  actor Human
-  participant UsbDetector
-end box
-" ))
-
-
-(ert-deftest plantuml-test-block-indentation/alt-end ()
-  "Test correct indentation of an alt-end block.
-The alt-keyword is NOT followed by some text."
-  (plantuml-test-indent-block
-   "
-alt
-A -> B
-end
-"
-   "
-alt
-  A -> B
-end
-" ))
-
-(ert-deftest plantuml-test-block-indentation/alt-end-with-label ()
-  "Test correct indentation of an alt-end block.
-The alt-keyword is followed by some text."
-  (plantuml-test-indent-block
-   "
-alt choice 1
-A -> B
-end
-"
-   "
-alt choice 1
-  A -> B
-end
-" ))
-
-(ert-deftest plantuml-test-block-indentation/alt-else-end ()
-  "Test correct indentation of an alt-else-end block."
-  (plantuml-test-indent-block
-   "
-alt choice 1
-A -> B
-else
-B -> C
-end
-"
-   "
-alt choice 1
-  A -> B
-else
-  B -> C
-end
-" ))
-
-(ert-deftest plantuml-test-block-indentation/opt ()
-  "Test correct indentation of an opt block.
-The opt-keyword is NOT followed by some text."
-  (plantuml-test-indent-block
-   "
-opt
-A -> B
-end
-"
-   "
-opt
-  A -> B
-end
-" ))
-
-(ert-deftest plantuml-test-block-indentation/opt-with-label ()
-  "Test correct indentation of an opt block.
-The opt-keyword is followed by some text."
-  (plantuml-test-indent-block
-   "
-opt event triggered
-A -> B
-end
-"
-   "
-opt event triggered
-  A -> B
-end
-" ))
-
-(ert-deftest plantuml-test-block-indentation/par ()
-  "Test correct indentation of a par block.
-The par-keyword is NOT followed by some text."
-  (plantuml-test-indent-block
-   "
-par
-A -> B
-else
-C -> B
-end
-"
-   "
-par
-  A -> B
-else
-  C -> B
-end
-" ))
-
-(ert-deftest plantuml-test-block-indentation/par-with-label ()
-  "Test correct indentation of a par block.
-The par-keyword is followed by some text."
-  (plantuml-test-indent-block
-   "
-par a text label
-A -> B
-else
-C -> B
-end
-"
-   "
-par a text label
-  A -> B
-else
-  C -> B
-end
-" ))
-
-(ert-deftest plantuml-test-block-indentation/group ()
-  "Test correct indentation of a group block.
-The group-keyword is NOT followed by some text."
-  (plantuml-test-indent-block
-   "
-group
-A -> B
-else
-C -> B
-end
-"
-   "
-group
-  A -> B
-else
-  C -> B
-end
-" ))
-
-(ert-deftest plantuml-test-block-indentation/group-with-label ()
-  "Test correct indentation of a group block.
-The group-keyword is followed by some text."
-  (plantuml-test-indent-block
-   "
-group my own label
-A -> B
-else
-C -> B
-end
-"
-   "
-group my own label
-  A -> B
-else
-  C -> B
-end
-" ))
-
-(ert-deftest plantuml-test-block-indentation/critical ()
-  "Test correct indentation of a critical block.
-The critical-keyword is NOT followed by some text."
-  (plantuml-test-indent-block
-   "
-critical
-A -> B
-else
-C -> B
-end
-"
-   "
-critical
-  A -> B
-else
-  C -> B
-end
-" ))
-
-(ert-deftest plantuml-test-block-indentation/critical-with-label ()
-  "Test correct indentation of a critical block.
-The critical-keyword is followed by some text."
-  (plantuml-test-indent-block
-   "
-critical my own label
-A -> B
-else
-C -> B
-end
-"
-   "
-critical my own label
-  A -> B
-else
-  C -> B
-end
-" ))
-
-
-(ert-deftest plantuml-test-block-indentation/alt-else-loop-group ()
-  "Test correct indentation of combination of alt-else, loop and group.
-
-This is taken from the plantuml homepage."
-  (plantuml-test-indent-block
-   "
-Alice -> Bob: Authentication Request
-
-alt successful case
-
-Bob -> Alice: Authentication Accepted
-
-else some kind of failure
-
-Bob -> Alice: Authentication Failure
-group My own label
-Alice -> Log : Log attack start
-loop 1000 times
-Alice -> Bob: DNS Attack
-end
-Alice -> Log : Log attack end
-end
-
-else Another type of failure
-
-Bob -> Alice: Please repeat
-
-end
-"
-   "
-Alice -> Bob: Authentication Request
-
-alt successful case
-
-  Bob -> Alice: Authentication Accepted
-
-else some kind of failure
-
-  Bob -> Alice: Authentication Failure
-  group My own label
-    Alice -> Log : Log attack start
-    loop 1000 times
-      Alice -> Bob: DNS Attack
-    end
-    Alice -> Log : Log attack end
-  end
-
-else Another type of failure
-
-  Bob -> Alice: Please repeat
-
-end
-"))
-
-
-(ert-deftest plantuml-test-block-indentation/note-as ()
-  "Test correct indentation of a note-as block."
-  (plantuml-test-indent-block
-   "
-note as N1
-This is a note
-end note
-"
-   "
-note as N1
-  This is a note
-end note
-"
-   ))
-
-(ert-deftest plantuml-test-block-indentation/activate-deactivate ()
-  "Test correct indentation of an activate-deactivate block."
-  (plantuml-test-indent-block
-   "
-activate participant_1
-participant_1 -> participant_2 : f()
-deactivate participant_1
-"
-   "
-activate participant_1
-  participant_1 -> participant_2 : f()
-deactivate participant_1
-"))
-
-(ert-deftest plantuml-test-block-indentation/activate-deactivate-nested ()
-  "Test correct indentation of two nested activate-deactivate blocks."
-  (plantuml-test-indent-block
-   "
-activate participant_1
-activate participant_2
-participant_1 -> participant_2 : f()
-deactivate participant_2
-deactivate participant_1
-"
-   "
-activate participant_1
-  activate participant_2
-    participant_1 -> participant_2 : f()
-  deactivate participant_2
-deactivate participant_1
-"))
-
 (provide 'plantuml-indentation-basics-test)
 
 ;;; plantuml-indentation-basics-test.el ends here
diff --git a/test/plantuml-indentation-class-test.el b/test/plantuml-indentation-class-test.el
index 7da686b..89f1d3f 100644
--- a/test/plantuml-indentation-class-test.el
+++ b/test/plantuml-indentation-class-test.el
@@ -313,8 +313,20 @@ together {
 "))
 
 
+(ert-deftest plantuml-test-block-indentation/class/package-empty ()
+  "Test correct indentation of an empty package block."
+  (plantuml-test-indent-block
+   "
+package APackage ()
+interface Inter
+"
+   "
+package APackage ()
+interface Inter
+"))
 
-(ert-deftest platuml-test-block-indentation/package-interface-nested ()
+
+(ert-deftest platuml-test-block-indentation/class/package-interface-nested ()
   "Test correct indentation of two nested blocks, a package and an interface
 Note: package is used in deployment and object diagrams as well, see there for more tests."
   (plantuml-test-indent-block
diff --git a/test/plantuml-indentation-commons-test.el b/test/plantuml-indentation-commons-test.el
index bde4683..f93b158 100644
--- a/test/plantuml-indentation-commons-test.el
+++ b/test/plantuml-indentation-commons-test.el
@@ -314,6 +314,21 @@ endlegend
 "))
 
 
+(ert-deftest plantuml-test-block-indentation/note-as ()
+  "Test correct indentation of a note-as block."
+  (plantuml-test-indent-block
+   "
+note as N1
+This is a note
+end note
+"
+   "
+note as N1
+  This is a note
+end note
+"
+   ))
+
 (provide 'plantuml-indentation-commons-test)
 
 ;;; plantuml-indentation-commons-test.el ends here
diff --git a/test/plantuml-indentation-sequence-test.el b/test/plantuml-indentation-sequence-test.el
new file mode 100644
index 0000000..c669c02
--- /dev/null
+++ b/test/plantuml-indentation-sequence-test.el
@@ -0,0 +1,313 @@
+;;; plantuml-indentation-sequence-test.el --- PlantUML Mode indentation tests   -*- lexical-binding: t; -*-
+
+;; Author: René Schmelzer
+;; Maintainer: Carlo Sciolla (skuro)
+;; URL: https://github.com/skuro/plantuml-mode
+
+;;; Commentary:
+
+;; Test indentation for sequence diagrams.
+
+;;; Code:
+
+
+(ert-deftest platuml-test-block-indentation/sequence/box ()
+  "Test correct indentation of a box block"
+  (plantuml-test-indent-block
+   "
+box \"Device with USB connector\"
+actor Human
+participant UsbDetector
+end box
+"
+   "
+box \"Device with USB connector\"
+  actor Human
+  participant UsbDetector
+end box
+" ))
+
+
+(ert-deftest plantuml-test-block-indentation/sequence/alt-end ()
+  "Test correct indentation of an alt-end block.
+The alt-keyword is NOT followed by some text."
+  (plantuml-test-indent-block
+   "
+alt
+A -> B
+end
+"
+   "
+alt
+  A -> B
+end
+" ))
+
+(ert-deftest plantuml-test-block-indentation/sequence/alt-end-with-label ()
+  "Test correct indentation of an alt-end block.
+The alt-keyword is followed by some text."
+  (plantuml-test-indent-block
+   "
+alt choice 1
+A -> B
+end
+"
+   "
+alt choice 1
+  A -> B
+end
+" ))
+
+(ert-deftest plantuml-test-block-indentation/sequence/alt-else-end ()
+  "Test correct indentation of an alt-else-end block."
+  (plantuml-test-indent-block
+   "
+alt choice 1
+A -> B
+else
+B -> C
+end
+"
+   "
+alt choice 1
+  A -> B
+else
+  B -> C
+end
+" ))
+
+(ert-deftest plantuml-test-block-indentation/sequence/opt ()
+  "Test correct indentation of an opt block.
+The opt-keyword is NOT followed by some text."
+  (plantuml-test-indent-block
+   "
+opt
+A -> B
+end
+"
+   "
+opt
+  A -> B
+end
+" ))
+
+(ert-deftest plantuml-test-block-indentation/sequence/opt-with-label ()
+  "Test correct indentation of an opt block.
+The opt-keyword is followed by some text."
+  (plantuml-test-indent-block
+   "
+opt event triggered
+A -> B
+end
+"
+   "
+opt event triggered
+  A -> B
+end
+" ))
+
+(ert-deftest plantuml-test-block-indentation/sequence/par ()
+  "Test correct indentation of a par block.
+The par-keyword is NOT followed by some text."
+  (plantuml-test-indent-block
+   "
+par
+A -> B
+else
+C -> B
+end
+"
+   "
+par
+  A -> B
+else
+  C -> B
+end
+" ))
+
+(ert-deftest plantuml-test-block-indentation/sequence/par-with-label ()
+  "Test correct indentation of a par block.
+The par-keyword is followed by some text."
+  (plantuml-test-indent-block
+   "
+par a text label
+A -> B
+else
+C -> B
+end
+"
+   "
+par a text label
+  A -> B
+else
+  C -> B
+end
+" ))
+
+(ert-deftest plantuml-test-block-indentation/sequence/group ()
+  "Test correct indentation of a group block.
+The group-keyword is NOT followed by some text."
+  (plantuml-test-indent-block
+   "
+group
+A -> B
+else
+C -> B
+end
+"
+   "
+group
+  A -> B
+else
+  C -> B
+end
+" ))
+
+(ert-deftest plantuml-test-block-indentation/sequence/group-with-label ()
+  "Test correct indentation of a group block.
+The group-keyword is followed by some text."
+  (plantuml-test-indent-block
+   "
+group my own label
+A -> B
+else
+C -> B
+end
+"
+   "
+group my own label
+  A -> B
+else
+  C -> B
+end
+" ))
+
+(ert-deftest plantuml-test-block-indentation/sequence/critical ()
+  "Test correct indentation of a critical block.
+The critical-keyword is NOT followed by some text."
+  (plantuml-test-indent-block
+   "
+critical
+A -> B
+else
+C -> B
+end
+"
+   "
+critical
+  A -> B
+else
+  C -> B
+end
+" ))
+
+(ert-deftest plantuml-test-block-indentation/sequence/critical-with-label ()
+  "Test correct indentation of a critical block.
+The critical-keyword is followed by some text."
+  (plantuml-test-indent-block
+   "
+critical my own label
+A -> B
+else
+C -> B
+end
+"
+   "
+critical my own label
+  A -> B
+else
+  C -> B
+end
+" ))
+
+
+(ert-deftest plantuml-test-block-indentation/sequence/activate-deactivate ()
+  "Test correct indentation of an activate-deactivate block."
+  (plantuml-test-indent-block
+   "
+activate participant_1
+participant_1 -> participant_2 : f()
+deactivate participant_1
+"
+   "
+activate participant_1
+  participant_1 -> participant_2 : f()
+deactivate participant_1
+"))
+
+(ert-deftest plantuml-test-block-indentation/sequence/activate-deactivate-nested ()
+  "Test correct indentation of two nested activate-deactivate blocks."
+  (plantuml-test-indent-block
+   "
+activate participant_1
+activate participant_2
+participant_1 -> participant_2 : f()
+deactivate participant_2
+deactivate participant_1
+"
+   "
+activate participant_1
+  activate participant_2
+    participant_1 -> participant_2 : f()
+  deactivate participant_2
+deactivate participant_1
+"))
+
+
+(ert-deftest plantuml-test-indentation/sequence-diagram ()
+  "Test correct indentation of plantuml sequence diagram elements.
+These code examples are taken from www.plantuml.com."
+  (plantuml-test-indent-block
+   "
+Alice -> Bob: Authentication Request
+
+alt successful case
+
+Bob -> Alice: Authentication Accepted
+
+else some kind of failure
+
+Bob -> Alice: Authentication Failure
+group My own label
+Alice -> Log : Log attack start
+loop 1000 times
+Alice -> Bob: DNS Attack
+end
+Alice -> Log : Log attack end
+end
+
+else Another type of failure
+
+Bob -> Alice: Please repeat
+
+end
+"
+   "
+Alice -> Bob: Authentication Request
+
+alt successful case
+
+  Bob -> Alice: Authentication Accepted
+
+else some kind of failure
+
+  Bob -> Alice: Authentication Failure
+  group My own label
+    Alice -> Log : Log attack start
+    loop 1000 times
+      Alice -> Bob: DNS Attack
+    end
+    Alice -> Log : Log attack end
+  end
+
+else Another type of failure
+
+  Bob -> Alice: Please repeat
+
+end
+"))
+
+
+(provide 'plantuml-indentation-sequence-test)
+
+;;; plantuml-indentation-sequence-test.el ends here