diff --git a/engine/shared/library/sharedMath/src/shared/PolySolver.cpp b/engine/shared/library/sharedMath/src/shared/PolySolver.cpp
index 872057d1..c4d61fb8 100755
--- a/engine/shared/library/sharedMath/src/shared/PolySolver.cpp
+++ b/engine/shared/library/sharedMath/src/shared/PolySolver.cpp
@@ -282,7 +282,7 @@ int PolySolver::solveQuartic( const double c[5], double s[4] )
 	}
 
 	static const double nan = sqrt(-1.0f);
-	if (isnan(D))
+	if (std::isnan(D))
 	{
 		s[0] = nan;
 		s[1] = nan;
@@ -293,7 +293,7 @@ int PolySolver::solveQuartic( const double c[5], double s[4] )
 		s[1] = (-1.0/4.0)*a3 + (1.0/2.0)*R - (1.0/2.0)*D;
 	}
 
-	if (isnan(E))
+	if (std::isnan(E))
 	{
 		s[2] = nan;
 		s[3] = nan;
diff --git a/engine/shared/library/sharedMath/src/shared/SphereTreeNode.h b/engine/shared/library/sharedMath/src/shared/SphereTreeNode.h
index 3d630b82..c33002dc 100755
--- a/engine/shared/library/sharedMath/src/shared/SphereTreeNode.h
+++ b/engine/shared/library/sharedMath/src/shared/SphereTreeNode.h
@@ -1574,10 +1574,10 @@ inline bool SphereTreeNode<ObjectType, ExtentAccessor>::isValidSphere(Sphere con
 	Vector const & center = sphere.getCenter();
 	float radius = sphere.getRadius();
 
-	if(isnan(center.x)) return false;
-	if(isnan(center.y)) return false;
-	if(isnan(center.z)) return false;
-	if(isnan(radius)) return false;
+	if(std::isnan(center.x)) return false;
+	if(std::isnan(center.y)) return false;
+	if(std::isnan(center.z)) return false;
+	if(std::isnan(radius)) return false;
 
 	if(!finite(center.x)) return false;
 	if(!finite(center.y)) return false;
diff --git a/engine/shared/library/sharedMath/src/shared/Transform.cpp b/engine/shared/library/sharedMath/src/shared/Transform.cpp
index ef35b3d0..3c43e539 100755
--- a/engine/shared/library/sharedMath/src/shared/Transform.cpp
+++ b/engine/shared/library/sharedMath/src/shared/Transform.cpp
@@ -842,7 +842,7 @@ bool Transform::isNaN() const
 				return true;
 			}
 #else
-			if(isnan(matrix[i][j]))
+			if(std::isnan(matrix[i][j]))
 			{
 				DEBUG_FATAL(true, ("nan"));
 				return true;
diff --git a/engine/shared/library/sharedMathArchive/src/shared/QuaternionArchive.h b/engine/shared/library/sharedMathArchive/src/shared/QuaternionArchive.h
index e8fbb32f..d27a6823 100755
--- a/engine/shared/library/sharedMathArchive/src/shared/QuaternionArchive.h
+++ b/engine/shared/library/sharedMathArchive/src/shared/QuaternionArchive.h
@@ -46,7 +46,7 @@ inline void get(ReadIterator & source, Quaternion & target)
 #ifdef _WIN32
 	if (_isnan(static_cast<double>(target.w)) || _isnan(static_cast<double>(target.x)) || _isnan(static_cast<double>(target.y)) || _isnan(static_cast<double>(target.z)))
 #else
-	if (isnan(target.w) || isnan(target.x) || isnan(target.y) || isnan(target.z))
+	if (std::isnan(target.w) || std::isnan(target.x) || std::isnan(target.y) || std::isnan(target.z))
 #endif
 	{
 		target.w = 1.0f;