diff --git a/poincare/Makefile b/poincare/Makefile
index ed3ecdfd7..00b0892c4 100644
--- a/poincare/Makefile
+++ b/poincare/Makefile
@@ -123,6 +123,7 @@ tests += $(addprefix poincare/test/,\
   addition.cpp\
   arithmetic.cpp\
   binomial_coefficient_layout.cpp\
+  complex_to_expression.cpp\
   convert_expression_to_text.cpp\
   division.cpp\
   factorial.cpp\
diff --git a/poincare/src/expression.cpp b/poincare/src/expression.cpp
index 27c027734..5235f0d68 100644
--- a/poincare/src/expression.cpp
+++ b/poincare/src/expression.cpp
@@ -847,7 +847,11 @@ template<typename T> Expression * Expression::complexToExpression(std::complex<T
       }
       if (r != 0 && th != 0) {
         Expression * arg = nullptr;
-        if (th > 0) {
+        if (th == 1.0) {
+          arg = new Symbol(Ion::Charset::IComplex);
+        } else if (th == -1.0) {
+          arg = new Opposite(new Symbol(Ion::Charset::IComplex), false);
+        } else if (th > 0) {
           arg = new Multiplication(CreateDecimal(th), new Symbol(Ion::Charset::IComplex), false);
         } else {
           arg = new Opposite(new Multiplication(CreateDecimal(-th), new Symbol(Ion::Charset::IComplex), false), false);
diff --git a/poincare/test/complex_to_expression.cpp b/poincare/test/complex_to_expression.cpp
new file mode 100644
index 000000000..720b51413
--- /dev/null
+++ b/poincare/test/complex_to_expression.cpp
@@ -0,0 +1,88 @@
+#include <quiz.h>
+#include <poincare.h>
+#include <ion.h>
+#include <assert.h>
+#include "helper.h"
+
+using namespace Poincare;
+
+QUIZ_CASE(poincare_complex_to_expression) {
+  assert_parsed_expression_evaluates_to<float>("0", "0");
+  assert_parsed_expression_evaluates_to<float>("0", "0", Radian, Polar);
+  assert_parsed_expression_evaluates_to<double>("0", "0");
+  assert_parsed_expression_evaluates_to<double>("0", "0", Radian, Polar);
+
+  assert_parsed_expression_evaluates_to<float>("10", "10");
+  assert_parsed_expression_evaluates_to<float>("-10", "-10");
+  assert_parsed_expression_evaluates_to<float>("100", "100");
+  assert_parsed_expression_evaluates_to<float>("0.1", "0.1");
+  assert_parsed_expression_evaluates_to<float>("0.1234567", "0.1234567");
+  assert_parsed_expression_evaluates_to<float>("0.12345678", "0.1234568");
+  assert_parsed_expression_evaluates_to<float>("1+2*I", "1+2*I");
+  assert_parsed_expression_evaluates_to<float>("1+I-I", "1");
+  assert_parsed_expression_evaluates_to<float>("1+I-1", "I");
+  assert_parsed_expression_evaluates_to<float>("1+I", "1+I");
+  assert_parsed_expression_evaluates_to<float>("3+I", "3+I");
+  assert_parsed_expression_evaluates_to<float>("3-I", "3-I");
+  assert_parsed_expression_evaluates_to<float>("3-I-3", "-I");
+
+  assert_parsed_expression_evaluates_to<float>("10", "10", Radian, Polar);
+  assert_parsed_expression_evaluates_to<float>("-10", "10*X^(3.141593*I)", Radian, Polar);
+  assert_parsed_expression_evaluates_to<float>("100", "100", Radian, Polar);
+  assert_parsed_expression_evaluates_to<float>("0.1", "0.1", Radian, Polar);
+  assert_parsed_expression_evaluates_to<float>("0.1234567", "0.1234567", Radian, Polar);
+  assert_parsed_expression_evaluates_to<float>("0.12345678", "0.1234568", Radian, Polar);
+  assert_parsed_expression_evaluates_to<float>("1+2*I", "2.236068*X^(1.107149*I)", Radian, Polar);
+  assert_parsed_expression_evaluates_to<float>("1+I-I", "1", Radian, Polar);
+  assert_parsed_expression_evaluates_to<float>("1+I-1", "X^(1.570796*I)", Radian, Polar);
+  assert_parsed_expression_evaluates_to<float>("1+I", "1.414214*X^(0.7853982*I)", Radian, Polar);
+  assert_parsed_expression_evaluates_to<float>("3+I", "3.162278*X^(0.3217506*I)", Radian, Polar);
+  assert_parsed_expression_evaluates_to<float>("3-I", "3.162278*X^(-0.3217506*I)", Radian, Polar);
+  assert_parsed_expression_evaluates_to<float>("3-I-3", "X^(-1.570796*I)", Radian, Polar);
+
+  assert_parsed_expression_evaluates_to<double>("10", "10");
+  assert_parsed_expression_evaluates_to<double>("-10", "-10");
+  assert_parsed_expression_evaluates_to<double>("100", "100");
+  assert_parsed_expression_evaluates_to<double>("0.1", "0.1");
+  assert_parsed_expression_evaluates_to<double>("0.12345678901234", "1.2345678901234E-1");
+  assert_parsed_expression_evaluates_to<double>("0.123456789012345", "1.2345678901235E-1");
+  assert_parsed_expression_evaluates_to<double>("1+2*I", "1+2*I");
+  assert_parsed_expression_evaluates_to<double>("1+I-I", "1");
+  assert_parsed_expression_evaluates_to<double>("1+I-1", "I");
+  assert_parsed_expression_evaluates_to<double>("1+I", "1+I");
+  assert_parsed_expression_evaluates_to<double>("3+I", "3+I");
+  assert_parsed_expression_evaluates_to<double>("3-I", "3-I");
+  assert_parsed_expression_evaluates_to<double>("3-I-3", "-I");
+
+  assert_parsed_expression_evaluates_to<double>("10", "10", Radian, Polar);
+  assert_parsed_expression_evaluates_to<double>("-10", "10*X^(3.1415926535898*I)", Radian, Polar);
+  assert_parsed_expression_evaluates_to<double>("100", "100", Radian, Polar);
+  assert_parsed_expression_evaluates_to<double>("0.1", "0.1", Radian, Polar);
+  assert_parsed_expression_evaluates_to<double>("0.1234567", "0.1234567", Radian, Polar);
+  assert_parsed_expression_evaluates_to<double>("0.12345678", "0.12345678", Radian, Polar);
+  assert_parsed_expression_evaluates_to<double>("1+2*I", "2.2360679775*X^(1.10714871779*I)", Radian, Polar, 12);
+  assert_parsed_expression_evaluates_to<double>("1+I-I", "1", Radian, Polar);
+  assert_parsed_expression_evaluates_to<double>("1+I-1", "X^(1.57079632679*I)", Radian, Polar, 12);
+  assert_parsed_expression_evaluates_to<double>("1+I", "1.41421356237*X^(0.785398163397*I)", Radian, Polar, 12);
+  assert_parsed_expression_evaluates_to<double>("3+I", "3.16227766017*X^(0.321750554397*I)", Radian, Polar,12);
+  assert_parsed_expression_evaluates_to<double>("3-I", "3.16227766017*X^(-0.321750554397*I)", Radian, Polar,12);
+  assert_parsed_expression_evaluates_to<double>("3-I-3", "X^(-1.57079632679*I)", Radian, Polar,12);
+
+  assert_parsed_expression_evaluates_to<double>("2+3*I", "3.60555127546*X^(0.982793723247*I)", Radian, Polar, 12);
+  assert_parsed_expression_evaluates_to<double>("3.60555127546*X^(0.982793723247*I)", "2+3*I", Radian, Cartesian, 12);
+  assert_parsed_expression_evaluates_to<float>("12.04159457879229548012824103*X^(1.4876550949*I)", "1+12*I", Radian, Cartesian, 6);
+  assert_parsed_expression_evaluates_to<float>("-2E20+2E20*I", "(-2E20)+2E20*I");
+  assert_parsed_expression_evaluates_to<float>("-2E20+2E20*I", "2.828427E20*X^(2.356194*I)", Radian, Polar);
+  assert_parsed_expression_evaluates_to<double>("1E155-1E155*I", "1E155-1E155*I");
+  assert_parsed_expression_evaluates_to<double>("1E155-1E155*I", "1.41421356237E155*X^(-0.785398163397*I)", Radian, Polar,12);
+
+  assert_parsed_expression_evaluates_to<float>("-2E100+2E100*I", "undef");
+  assert_parsed_expression_evaluates_to<double>("-2E360+2E360*I", "undef");
+  assert_parsed_expression_evaluates_to<float>("-2E100+2E10*I", "undef");
+  assert_parsed_expression_evaluates_to<double>("-2E360+2*I", "undef");
+  assert_parsed_expression_evaluates_to<float>("undef+2E100*I", "undef");
+  assert_parsed_expression_evaluates_to<double>("-2E360+undef*I", "undef");
+
+  assert_parsed_expression_evaluates_to<double>("2*X^(I)", "2*X^I", Radian, Polar, 5);
+  assert_parsed_expression_evaluates_to<double>("2*X^(-I)", "2*X^(-I)", Radian, Polar, 5);
+}