diff --git a/src/SpriteLang-Tests/SpriteDataNegTest.class.st b/src/SpriteLang-Tests/SpriteDataNegTest.class.st
new file mode 100644
index 000000000..9d2a888bc
--- /dev/null
+++ b/src/SpriteLang-Tests/SpriteDataNegTest.class.st
@@ -0,0 +1,24 @@
+Class {
+	#name : #SpriteDataNegTest,
+	#superclass : #SpriteLangNegTest,
+	#category : #'SpriteLang-Tests-Simple'
+}
+
+{ #category : #tests }
+SpriteDataNegTest >> test_TwoIsNotTerminal [
+	self processString: '
+type two =
+  | A
+  | B
+  ;
+
+⟦val cassert : bool[b|b] => int⟧
+let cassert = (b) => { 0 };
+
+⟦val main : two => two => int⟧
+let main = (x, y) => {
+  let ok = x == y;
+  cassert(ok)
+};
+'
+]
diff --git a/src/SpriteLang-Tests/SpriteDataPosTest.class.st b/src/SpriteLang-Tests/SpriteDataPosTest.class.st
new file mode 100644
index 000000000..b19bcee6a
--- /dev/null
+++ b/src/SpriteLang-Tests/SpriteDataPosTest.class.st
@@ -0,0 +1,23 @@
+Class {
+	#name : #SpriteDataPosTest,
+	#superclass : #SpriteLangPosTest,
+	#category : #'SpriteLang-Tests-Simple'
+}
+
+{ #category : #tests }
+SpriteDataPosTest >> test_VoidIsTerminal [
+	self processString: '
+type void =
+  | Nil
+  ;
+
+⟦val cassert : bool[b|b] => int⟧
+let cassert = (b) => { 0 };
+
+⟦val main : void => void => int⟧
+let main = (x, y) => {
+  let ok = x == y;
+  cassert(ok)
+};
+'
+]