diff -r 522fed67ed37 src/backend/APT/APTFileIO.cpp
--- src/backend/APT/APTFileIO.cpp	Mon Aug 28 13:47:41 2017 +0100
+++ src/backend/APT/APTFileIO.cpp	Mon Aug 28 13:49:44 2017 +0100
@@ -956,7 +956,7 @@
 		ASSERT(forceEndian < 3);
 #ifdef __LITTLE_ENDIAN__
 		endianFlip=(forceEndian == 2);
-#elif __BIG_ENDIAN
+#elif defined(__BIG_ENDIAN__)
 		endianFlip=(forceEndian == 1);
 #endif
 	}
@@ -1225,7 +1225,7 @@
 
 			//assign the ID as the mass to charge
 			h.setMassToCharge(*( (short*)(buffer+12) ));
-#elif __BIG_ENDIAN__
+#elif defined(__BIG_ENDIAN__)
 			{
 			Point3D pt((float*)(buffer));
 			pt.switchEndian();