diff --git a/apps/shared/cartesian_function.cpp b/apps/shared/cartesian_function.cpp
index 9b2004e5b..f915acd33 100644
--- a/apps/shared/cartesian_function.cpp
+++ b/apps/shared/cartesian_function.cpp
@@ -203,7 +203,7 @@ CartesianFunction::CartesianFunctionRecordDataBuffer * CartesianFunction::record
 
 template<typename T>
 Coordinate2D<T> CartesianFunction::templatedApproximateAtParameter(T t, Poincare::Context * context) const {
-  if (isCircularlyDefined(context)) {
+  if (isCircularlyDefined(context) || t < tMin() || t > tMax()) {
     return Coordinate2D<T>(NAN, NAN);
   }
   constexpr int bufferSize = CodePoint::MaxCodePointCharLength + 1;