diff --git a/src/core/domains/slice/codac_Slice.cpp b/src/core/domains/slice/codac_Slice.cpp
index 5c1f0a58a..af4755149 100644
--- a/src/core/domains/slice/codac_Slice.cpp
+++ b/src/core/domains/slice/codac_Slice.cpp
@@ -195,7 +195,7 @@ namespace codac
         p_eval.second |= output_gate().ub();
       }
 
-      if(t.is_subset(tdomain()))
+      if(t.is_subset(tdomain()) && t != m_tdomain.lb() && t != m_tdomain.ub())
       {
         p_eval.first |= m_codomain.lb();
         p_eval.second |= m_codomain.ub();
diff --git a/tests/core/tests_ctc_delay.cpp b/tests/core/tests_ctc_delay.cpp
index ee3dcb1f3..c4eaad6bd 100644
--- a/tests/core/tests_ctc_delay.cpp
+++ b/tests/core/tests_ctc_delay.cpp
@@ -24,7 +24,7 @@ TEST_CASE("CtcDelay")
     Interval pi = Interval::pi();
     ctc_delay.contract(pi, x, y);
 
-    if(false)
+    if(VIBES_DRAWING)
     {
       vibes::beginDrawing();
       VIBesFigTube fig_x("delay x", &x);
@@ -51,7 +51,7 @@ TEST_CASE("CtcDelay")
     ctc_delay.contract(delay, x, y);
     ctc_delay.contract(delay, x, y);
 
-    if(true)
+    if(VIBES_DRAWING)
     {
       vibes::beginDrawing();
       VIBesFigTube fig_x("delay x", &x);