diff --git a/poincare/src/addition.cpp b/poincare/src/addition.cpp
index 80361ed50..21a12a206 100644
--- a/poincare/src/addition.cpp
+++ b/poincare/src/addition.cpp
@@ -96,7 +96,7 @@ Addition Addition::Builder() {
 
 Addition Addition::Builder(Expression * children, size_t numberOfChildren) {
   Addition a = Addition::Builder();
-  for (int i = 0; i < numberOfChildren; i++) {
+  for (size_t i = 0; i < numberOfChildren; i++) {
     a.addChildAtIndexInPlace(children[i], i, i);
   }
   return a;
diff --git a/poincare/src/multiplication.cpp b/poincare/src/multiplication.cpp
index f87398e91..52efbe73d 100644
--- a/poincare/src/multiplication.cpp
+++ b/poincare/src/multiplication.cpp
@@ -117,7 +117,7 @@ Multiplication Multiplication::Builder() {
 
 Multiplication Multiplication::Builder(Expression * children, size_t numberOfChildren) {
   Multiplication m = Multiplication::Builder();
-  for (int i = 0; i < numberOfChildren; i++) {
+  for (size_t i = 0; i < numberOfChildren; i++) {
     m.addChildAtIndexInPlace(children[i], i, i);
   }
   return m;