diff --git a/poincare/include/poincare/function.h b/poincare/include/poincare/function.h
index 5944e2ae0..bd49e8fd8 100644
--- a/poincare/include/poincare/function.h
+++ b/poincare/include/poincare/function.h
@@ -46,9 +46,9 @@ private:
 
 class Function : public SymbolAbstract {
 public:
-  explicit Function(const char * name);
+  Function(const char * name, size_t length);
   Function(const FunctionNode * n) : SymbolAbstract(n) {}
-  explicit Function(const char * name, Expression child) : Function(name) {
+  Function(const char * name, size_t length, Expression child) : Function(name, length) {
     replaceChildAtIndexInPlace(0, child);
   }
 
diff --git a/poincare/src/function.cpp b/poincare/src/function.cpp
index 19b9a659a..f538ddb0a 100644
--- a/poincare/src/function.cpp
+++ b/poincare/src/function.cpp
@@ -87,10 +87,10 @@ Evaluation<T> FunctionNode::templatedApproximate(Context& context, Preferences::
   return e.approximateToEvaluation<T>(newContext, angleUnit);
 }
 
-Function::Function(const char * name) :
-  Function(TreePool::sharedPool()->createTreeNode<FunctionNode>(SymbolAbstract::AlignedNodeSize(strlen(name), sizeof(FunctionNode))))
+Function::Function(const char * name, size_t length) :
+  Function(TreePool::sharedPool()->createTreeNode<FunctionNode>(SymbolAbstract::AlignedNodeSize(length, sizeof(FunctionNode))))
 {
-  static_cast<FunctionNode *>(Expression::node())->setName(name, strlen(name));
+  static_cast<FunctionNode *>(Expression::node())->setName(name, length);
 }
 
 Expression Function::replaceSymbolWithExpression(const SymbolAbstract & symbol, const Expression & expression) {