diff --git a/test/bad/clock_causality.ept b/test/bad/clock_causality.ept
new file mode 100644
index 0000000..d8b3d0b
--- /dev/null
+++ b/test/bad/clock_causality.ept
@@ -0,0 +1,13 @@
+node cross<<l:int>>(x:int) returns (y:int; c:bool)
+let
+  c = (0 fby y) = l;
+  y = merge c (true -> x) (false -> 0);
+tel
+
+node main(x:int) returns (z:int)
+var y,t : int; c : bool;
+let
+  y = 0 fby (y+1);
+  (t,c) = cross<<4>>(y);
+  z = merge c (true -> y + t) (false -> 0)
+tel
diff --git a/test/bad/clock_dep.ept b/test/bad/clock_dep.ept
new file mode 100644
index 0000000..906aab4
--- /dev/null
+++ b/test/bad/clock_dep.ept
@@ -0,0 +1,5 @@
+node cross<<l:int>>(x:int; x2:int;  c:bool) returns (y:int; c2:bool)
+let
+  c2 = c;
+  y = x + (x2 when c2) ;
+tel
diff --git a/test/good/clock_causality.ept b/test/good/clock_causality.ept
new file mode 100644
index 0000000..097ef2b
--- /dev/null
+++ b/test/good/clock_causality.ept
@@ -0,0 +1,13 @@
+node cross<<l:int>>(x:int) returns (y:int; c:bool)
+let
+  c = x = l;
+  y = x when c;
+tel
+
+node main(x:int) returns (z:int)
+var y,t : int; c : bool;
+let
+  y = 0 fby (y+1);
+  (t,c) = cross<<4>>(x);
+  z = merge c (true -> y + t) (false -> 0)
+tel