diff --git a/AMBuildScript b/AMBuildScript
index 55e37a5..c6b6b7b 100644
--- a/AMBuildScript
+++ b/AMBuildScript
@@ -133,6 +133,7 @@ class MMS:
 						(self.vendor == 'clang' and cxx.majorVersion >= 3):
 					self.compiler.AddToListVar('CXXFLAGS', '-Wno-delete-non-virtual-dtor')
 				self.compiler.AddToListVar('CDEFINES', 'HAVE_STDINT_H')
+				self.compiler.AddToListVar('CDEFINES', 'GNUC')
 				if self.vendor == 'gcc':
 					self.compiler.AddToListVar('CFLAGS', '-mfpmath=sse')
 			elif isinstance(cxx, Cpp.MSVC):
@@ -195,6 +196,7 @@ class MMS:
 			#Platform-specifics
 			if AMBuild.target['platform'] == 'linux':
 				self.compiler.AddToListVar('CDEFINES', '_LINUX')
+				self.compiler.AddToListVar('CDEFINES', 'POSIX')
 				if self.vendor == 'gcc':
 					self.compiler.AddToListVar('POSTLINKFLAGS', '-static-libgcc')
 				if self.vendor == 'clang':
@@ -202,6 +204,7 @@ class MMS:
 			elif AMBuild.target['platform'] == 'darwin':
 				self.compiler.AddToListVar('CDEFINES', 'OSX')
 				self.compiler.AddToListVar('CDEFINES', '_OSX')
+				self.compiler.AddToListVar('CDEFINES', 'POSIX')
 				self.compiler.AddToListVar('POSTLINKFLAGS', '-mmacosx-version-min=10.5')
 				self.compiler.AddToListVar('POSTLINKFLAGS', ['-arch', 'i386'])
 				self.compiler.AddToListVar('POSTLINKFLAGS', '-lstdc++')
@@ -363,7 +366,7 @@ class MMS:
 			if AMBuild.target['platform'] == 'windows':
 				compiler['CDEFINES'].extend(['COMPILER_MSVC', 'COMPILER_MSVC32'])
 			else:
-				compiler['CDEFINES'].extend(['COMPILER_GCC', 'POSIX'])
+				compiler['CDEFINES'].extend(['COMPILER_GCC'])
 
 		if sdk == 'ep1':
 			if AMBuild.target['platform'] == 'linux':