diff --git a/poincare/src/multiplication.cpp b/poincare/src/multiplication.cpp
index 16e23a6db..e11cd00b8 100644
--- a/poincare/src/multiplication.cpp
+++ b/poincare/src/multiplication.cpp
@@ -42,6 +42,7 @@ void Multiplication::turnIntoPositive() {
       const_cast<Expression *>(operand(i))->turnIntoPositive();
     }
   }
+  immediateSimplify();
 }
 
 template<typename T>
@@ -305,7 +306,6 @@ Expression * Multiplication::mergeNegativePower() {
     if (operand(i)->type() == Type::Power && operand(i)->operand(1)->sign() < 0) {
       const Expression * e = operand(i);
       const_cast<Expression *>(e->operand(1))->turnIntoPositive();
-      // TODO: should we call const_cast<Expression *>(e->operand(1))->immediateSimplify
       removeOperand(e, false);
       m->addOperands(&e, 1);
       const_cast<Expression *>(e)->immediateSimplify();
diff --git a/poincare/src/power.cpp b/poincare/src/power.cpp
index 9e091d0cb..942a7de1f 100644
--- a/poincare/src/power.cpp
+++ b/poincare/src/power.cpp
@@ -363,8 +363,6 @@ Expression * Power::createDenominator() {
   if (operand(1)->sign() < 0) {
     Expression * denominator = clone();
     const_cast<Expression *>(denominator->operand(1))->turnIntoPositive();
-
-    const_cast<Expression *>(denominator->operand(1))->simplify();
     if (denominator->operand(1)->type() == Type::Rational && static_cast<Rational *>((Expression *)denominator->operand(1))->isOne()) {
       delete denominator;
       return operand(0)->clone();