diff --git a/poincare/include/poincare/integer.h b/poincare/include/poincare/integer.h
index ec3391ca4..a93d714d9 100644
--- a/poincare/include/poincare/integer.h
+++ b/poincare/include/poincare/integer.h
@@ -5,6 +5,7 @@
 #include <stdint.h>
 
 typedef uint32_t native_uint_t;
+typedef uint64_t double_native_uint_t;
 
 class Integer : public Expression {
   public:
@@ -16,6 +17,7 @@ class Integer : public Expression {
     virtual bool identicalTo(Expression * e);
     //Integer add(Integer * i);
     const Integer operator+(const Integer &other) const;
+    const Integer operator*(const Integer &other) const;
     bool operator==(const Integer &other) const;
   protected:
     virtual void layout();
diff --git a/poincare/src/integer.cpp b/poincare/src/integer.cpp
index 373035cbe..bc67a81a4 100644
--- a/poincare/src/integer.cpp
+++ b/poincare/src/integer.cpp
@@ -69,6 +69,31 @@ const Integer Integer::operator+(const Integer &other) const {
   return Integer(bits, sumSize);
 }
 
+const Integer Integer::operator*(const Integer &other) const {
+  uint16_t productSize = other.m_numberOfBits + m_numberOfBits;
+  uint16_t intArraySize = arraySize(productSize);
+  native_uint_t * bits = (native_uint_t *)malloc(intArraySize*sizeof(native_uint_t));
+  memset(bits, 0, intArraySize*sizeof(native_uint_t));
+
+  uint16_t myArraySize = arraySize(m_numberOfBits);
+  uint16_t otherArraySize = arraySize(other.m_numberOfBits);
+
+  native_uint_t carry = 0;
+  for (uint16_t i=0; i<myArraySize; i++) {
+    native_uint_t a = m_bits[i];
+    carry = 0;
+    for (uint16_t j=0; j<otherArraySize; j++) {
+      native_uint_t b = other.m_bits[i];
+      double_native_uint_t p = a*b + carry; // TODO: Prove it cannot overflow
+      m_bits[i+j] += (native_uint_t)p; // Only the last "digit"
+      carry = p>>32; //FIXME: 32 is hardcoded here!
+    }
+    m_bits[i+otherArraySize] = carry;
+  }
+
+  return Integer(bits, productSize);
+}
+
 /*
  char * Integer::bits() {
   if (m_numberOfBits > INTEGER_IMMEDIATE_LIMIT) {