diff --git a/DesktopEditor/agg-2.4/include/test_grads/custom_gradients.h b/DesktopEditor/agg-2.4/include/test_grads/custom_gradients.h
index c9120e1b6e..ff45a566fe 100644
--- a/DesktopEditor/agg-2.4/include/test_grads/custom_gradients.h
+++ b/DesktopEditor/agg-2.4/include/test_grads/custom_gradients.h
@@ -3,6 +3,7 @@
 #include <math.h>
 #include "../../../graphics/AggPlusEnums.h"
 #include "../../../graphics/structures.h"
+#include <cmath>
 #ifndef M_1_PI
 #define M_1_PI 0.318309886183790671538
 #endif
@@ -15,10 +16,6 @@
 #endif
 #endif
 
-#ifdef _WIN32
-#define isnanf _isnanf
-#endif
-
 #ifndef SHADING_PDF
 #define SHADING_PDF
 
@@ -558,7 +555,7 @@ namespace agg
         inline float calculate_param(const float &x, const float &y)
         {
             float t = calculate->eval(x, y);
-            if(isnanf(t))
+            if(std::isnan(t))
                 return t;
             
             if (t < m_oGradientInfo.shading.function.get_x_min() && !m_oGradientInfo.continue_shading_b)