diff --git a/DeveloperTools/CodeTesting/ScatteringTests/cu50_test.cpp b/DeveloperTools/CodeTesting/ScatteringTests/cu50_test.cpp
index 2d033737..b848f4b0 100644
--- a/DeveloperTools/CodeTesting/ScatteringTests/cu50_test.cpp
+++ b/DeveloperTools/CodeTesting/ScatteringTests/cu50_test.cpp
@@ -236,7 +236,8 @@ int main(int argc, char* argv[])
 			double coords[] = {ip->x(), ip->xp(), ip->y() - y_offset, ip->yp(), -ip->dp()};
 			for(int i = 0; i < 5; i++)
 			{
-                          if(isnan(coords[i])) continue; // RJB 
+				if(std::isnan(coords[i]))
+					continue; // RJB
 				// beware, this can rollover when x is big
 				int bin_x = ((coords[i] - bin_mins[i]) / (bin_maxs[i] - bin_mins[i]) * (nbins)) + 1; // +1 because bin zero for outliers
 				// so handle end bins, by check against x, not bin
diff --git a/Merlin++/Aperture.cpp b/Merlin++/Aperture.cpp
index 99af16f8..2fa87fa9 100644
--- a/Merlin++/Aperture.cpp
+++ b/Merlin++/Aperture.cpp
@@ -9,7 +9,6 @@
 #include <string>
 #include <vector>
 #include <map>
-#include <math.h>
 #define _USE_MATH_DEFINES
 #include <cmath>
 #include <algorithm>
diff --git a/Merlin++/Aperture.h b/Merlin++/Aperture.h
index bfffddf5..ff114c77 100644
--- a/Merlin++/Aperture.h
+++ b/Merlin++/Aperture.h
@@ -11,7 +11,6 @@
 #include <iostream>
 #include <string>
 #include <map>
-#include <math.h>
 #define _USE_MATH_DEFINES
 #include <cmath>
 #include "DataTable.h"
diff --git a/Merlin++/AxisRotations.h b/Merlin++/AxisRotations.h
index 112410d0..46a8dba8 100644
--- a/Merlin++/AxisRotations.h
+++ b/Merlin++/AxisRotations.h
@@ -9,7 +9,7 @@
 #define AxisRotations_h 1
 
 #include "merlin_config.h"
-#include <math.h>
+#include <cmath>
 #include "Space3D.h"
 #include "RotationType.h"
 #include "Rot3Drep.h"
diff --git a/Merlin++/CollimatorPotentialModels.cpp b/Merlin++/CollimatorPotentialModels.cpp
index 964f4ed7..7fe358fd 100644
--- a/Merlin++/CollimatorPotentialModels.cpp
+++ b/Merlin++/CollimatorPotentialModels.cpp
@@ -5,7 +5,7 @@
  * This file is derived from software bearing the copyright notice in merlin4_copyright.txt
  */
 
-#include <math.h>
+#include <cmath>
 
 #include "CollimatorPotentialModels.h"