diff --git a/poincare/src/expression.cpp b/poincare/src/expression.cpp
index 64045703e..4e8e4f4e0 100644
--- a/poincare/src/expression.cpp
+++ b/poincare/src/expression.cpp
@@ -168,9 +168,15 @@ bool Expression::IsMatrix(const Expression * e) {
 int Expression::SimplificationOrder(const Expression * e1, const Expression * e2) {
   if (e1->type() > e2->type()) {
     return -(e2->simplificationOrderGreaterType(e1));
+    if (shouldStopProcessing()) {
+      return 1;
+    }
   } else if (e1->type() == e2->type()) {
     return e1->simplificationOrderSameType(e2);
   } else {
+    if (shouldStopProcessing()) {
+      return -1;
+    }
     return e1->simplificationOrderGreaterType(e2);
   }
 }
diff --git a/poincare/src/power.cpp b/poincare/src/power.cpp
index a81e2520a..155065413 100644
--- a/poincare/src/power.cpp
+++ b/poincare/src/power.cpp
@@ -34,6 +34,9 @@ Expression * Power::clone() const {
 }
 
 Expression::Sign Power::sign() const {
+  if (shouldStopProcessing()) {
+    return Sign::Unknown;
+  }
   if (operand(0)->sign() == Sign::Positive && operand(1)->sign() != Sign::Unknown) {
     return Sign::Positive;
   }