diff --git a/poincare/src/absolute_value.cpp b/poincare/src/absolute_value.cpp
index 16d243202..97356e023 100644
--- a/poincare/src/absolute_value.cpp
+++ b/poincare/src/absolute_value.cpp
@@ -22,6 +22,11 @@ Expression * AbsoluteValue::immediateSimplify() {
   if (operand(0)->sign() > 0) {
     return replaceWith(const_cast<Expression *>(operand(0)), true);
   }
+  if (operand(0)->sign() < 0) {
+    Expression * op = const_cast<Expression *>(operand(0));
+    Expression * newOp = op->turnIntoPositive();
+    return replaceWith(newOp, true);
+  }
   return this;
 }
 
diff --git a/poincare/test/simplify_easy.cpp b/poincare/test/simplify_easy.cpp
index 3d54d7220..259c1f7d6 100644
--- a/poincare/test/simplify_easy.cpp
+++ b/poincare/test/simplify_easy.cpp
@@ -110,6 +110,7 @@ QUIZ_CASE(poincare_simplify_easy) {
   assert_parsed_expression_simplify_to("R(x*144*P^2)", "12*P*R(x)");
   assert_parsed_expression_simplify_to("R(x*144*P)", "12*R(xP)");
   assert_parsed_expression_simplify_to("abs(P)", "P");
+  assert_parsed_expression_simplify_to("abs(-P)", "P");
   assert_parsed_expression_simplify_to("R(2)*R(3)", "R(6)");
   assert_parsed_expression_simplify_to("2*2^P", "2*2^P");
   assert_parsed_expression_simplify_to("A-A", "0");