diff --git a/poincare/src/matrix.cpp b/poincare/src/matrix.cpp
index 05fd33951..eb5ffdf46 100644
--- a/poincare/src/matrix.cpp
+++ b/poincare/src/matrix.cpp
@@ -107,7 +107,7 @@ void Matrix::addChildrenAsRowInPlace(TreeByReference t, int i) {
 
 int Matrix::rank(Context & context, Preferences::AngleUnit angleUnit, bool inPlace) {
   Matrix m = inPlace ? *this : clone().convert<Matrix>();
-  Matrix m = rowCanonize(context, angleUnit);
+  m = m.rowCanonize(context, angleUnit);
   int rank = m.numberOfRows();
   int i = rank-1;
   while (i >= 0) {