diff --git a/poincare/src/power.cpp b/poincare/src/power.cpp
index 0c8b06f14..28421dc0c 100644
--- a/poincare/src/power.cpp
+++ b/poincare/src/power.cpp
@@ -270,9 +270,11 @@ Expression * Power::shallowReduce(Context& context, AngleUnit angleUnit) {
     if (operand(1)->type() == Type::Rational && static_cast<Rational *>(editableOperand(1))->denominator().isOne()) {
       return simplifyPowerMultiplication(m, editableOperand(1), context, angleUnit);
     }
-    // (a*b*...)^r -> |a|^r*(sign(a)*b*)^r if a rational
+    // (a*b*...)^r -> |a|^r*(sign(a)*b*...)^r if a rational
     for (int i = 0; i < m->numberOfOperands(); i++) {
-      if (m->operand(i)->sign() == Sign::Positive || m->operand(i)->type() == Type::Rational) {
+      // a is signed and a != -1
+      if (m->operand(i)->sign() != Sign::Unknown && (m->operand(i)->type() != Type::Rational || !static_cast<const Rational *>(m->operand(i))->isMinusOne())) {
+      //if (m->operand(i)->sign() == Sign::Positive || m->operand(i)->type() == Type::Rational) {
         Expression * r = editableOperand(1);
         Expression * rCopy = r->clone();
         Expression * factor = m->editableOperand(i);
diff --git a/poincare/test/simplify_easy.cpp b/poincare/test/simplify_easy.cpp
index 76dcbc515..e8b9f03a4 100644
--- a/poincare/test/simplify_easy.cpp
+++ b/poincare/test/simplify_easy.cpp
@@ -478,6 +478,7 @@ QUIZ_CASE(poincare_simplify_easy) {
   assert_parsed_expression_simplify_to("10^log(P)", "P");
   assert_parsed_expression_simplify_to("log(1/R(2))", "-log(2)/2");
   assert_parsed_expression_simplify_to("log(-I)", "log(-I)");
+  assert_parsed_expression_simplify_to("R(-I)", "R(-I)");
 
   /* This does not work but should not as it is above k_primorial32 = 1*3*5*7*11*... (product of first 32 primes. */
   //assert_parsed_expression_simplify_to("1881676377434183981909562699940347954480361860897069^(1/3)", "123456789123456789");