diff --git a/poincare/include/poincare/decimal.h b/poincare/include/poincare/decimal.h
index 90e58005b..60b7e69ba 100644
--- a/poincare/include/poincare/decimal.h
+++ b/poincare/include/poincare/decimal.h
@@ -53,6 +53,9 @@ public:
   }
 
   // Comparison
+  /* Warning: Decimal(mantissa: 1000, exponent: 3) and Decimal(mantissa: 1, exponent: 3)
+   * are strictly ordered with the SimplificationOrder although they are equal
+   * with the usual math order (1.000E3 == 1E3). */
   int simplificationOrderSameType(const ExpressionNode * e, bool ascending, bool canBeInterrupted) const override;
 
   // Simplification
diff --git a/poincare/src/decimal.cpp b/poincare/src/decimal.cpp
index 5fb7ef0e2..62c72ecb9 100644
--- a/poincare/src/decimal.cpp
+++ b/poincare/src/decimal.cpp
@@ -81,9 +81,7 @@ int DecimalNode::simplificationOrderSameType(const ExpressionNode * e, bool asce
   } else {
     assert(m_exponent == other->m_exponent);
     assert(exponent() == other->exponent());
-    double approx0 = templatedApproximate<double>();
-    double approx1 = other->templatedApproximate<double>();
-    return (approx0 == approx1 ? 0 : (approx0 < approx1 ? -1 : 1));
+    unsignedComparison = Integer::NaturalOrder(unsignedMantissa(), other->unsignedMantissa());
   }
   return ((int)Number(this).sign())*unsignedComparison;
 }
diff --git a/poincare/test/expression.cpp b/poincare/test/expression.cpp
index a7c69f080..a18c0bf5a 100644
--- a/poincare/test/expression.cpp
+++ b/poincare/test/expression.cpp
@@ -48,8 +48,9 @@ QUIZ_CASE(poincare_expression_decimal_constructor) {
   assert_pool_size(initialPoolSize+4);
 
   assert_equal(Decimal::Builder("25", 3), Decimal::Builder("25", 3));
-  assert_equal(Decimal::Builder("1000", -3), Decimal::Builder("1", -3));
-  assert_equal(Decimal::Builder("1000", 3), Decimal::Builder("1", 3));
+  assert_equal(Decimal::Builder("25", 3), Decimal::Builder(25, 3));
+  assert_not_equal(Decimal::Builder("1000", -3), Decimal::Builder("1", -3));
+  assert_not_equal(Decimal::Builder("1000", 3), Decimal::Builder("1", 3));
   assert_not_equal(Decimal::Builder(123,234), Decimal::Builder(42, 108));
   assert_not_equal(Decimal::Builder(12,2), Decimal::Builder(123, 2));
   assert_not_equal(Decimal::Builder(1234,2), Decimal::Builder(1234,3));