diff --git a/src_main/io/pisharedmemory.cpp b/src_main/io/pisharedmemory.cpp
index e283f41a..3e5714ba 100644
--- a/src_main/io/pisharedmemory.cpp
+++ b/src_main/io/pisharedmemory.cpp
@@ -18,6 +18,9 @@
 */
 #include "piincludes_p.h"
 #include "pisharedmemory.h"
+#if defined(LINUX) || defined(MAC_OS)
+#  define SHM_POSIX
+#endif
 #ifdef WINDOWS
 
 #endif
@@ -25,9 +28,10 @@
 
 #endif
 #ifdef MAC_OS
+//#  include <fcntl.h>
 
 #endif
-#ifdef LINUX
+#ifdef SHM_POSIX
 #  include <fcntl.h>
 #  include <sys/stat.h>
 #  include <sys/mman.h>
@@ -62,7 +66,7 @@ PRIVATE_DEFINITION_START(PISharedMemory)
 	HANDLE map;
 	void * data;
 #endif
-#ifdef LINUX
+#ifdef SHM_POSIX
 	void * data;
 	bool owner;
 #endif
@@ -108,7 +112,7 @@ bool PISharedMemory::openDevice() {
 	}
 	//piCout << PRIVATE->map << PRIVATE->data;
 #endif
-#ifdef LINUX
+#ifdef SHM_POSIX
 	PRIVATE->name = ("/pip_shm_" + path()).toByteArray();
 	PRIVATE->name.push_back(0);
 	int fd = shm_open((const char *)PRIVATE->name.data(), O_RDWR, 0777);
@@ -143,7 +147,7 @@ bool PISharedMemory::closeDevice() {
 	if (PRIVATE->data) UnmapViewOfFile(PRIVATE->data);
 	if (PRIVATE->map) CloseHandle(PRIVATE->map);
 #endif
-#ifdef LINUX
+#ifdef SHM_POSIX
 	//piCoutObj << "close" << PIString(PRIVATE->name) << PRIVATE->data;
 	if (PRIVATE->data) munmap(PRIVATE->data, dsize);
 	if (PRIVATE->owner) {
@@ -183,7 +187,7 @@ void PISharedMemory::initPrivate() {
 	PRIVATE->map = 0;
 	PRIVATE->data = 0;
 #endif
-#ifdef LINUX
+#ifdef SHM_POSIX
 	PRIVATE->data = 0;
 	PRIVATE->owner = false;
 #endif
@@ -195,7 +199,7 @@ PIByteArray PISharedMemory::readAll() {
 #ifdef WINDOWS
 	if (!PRIVATE->data) return PIByteArray();
 #endif
-#ifdef LINUX
+#ifdef SHM_POSIX
 	if (!PRIVATE->data) return PIByteArray();
 #endif
 	PIByteArray a(dsize);
@@ -229,7 +233,7 @@ int PISharedMemory::read(void * read_to, int max_size, int offset) {
 	CopyMemory(read_to, &(((char*)(PRIVATE->data))[offset]), max_size);
 	return max_size;
 #endif
-#ifdef LINUX
+#ifdef SHM_POSIX
 	if (!PRIVATE->data) return -1;
 	memcpy(read_to, &(((char*)(PRIVATE->data))[offset]), max_size);
 	return max_size;
@@ -249,7 +253,7 @@ int PISharedMemory::write(const void * data, int max_size, int offset) {
 	CopyMemory(&(((char*)(PRIVATE->data))[offset]), data, max_size);
 	return max_size;
 #endif
-#ifdef LINUX
+#ifdef SHM_POSIX
 	if (!PRIVATE->data) return -1;
 	memcpy(&(((char*)(PRIVATE->data))[offset]), data, max_size);
 	return max_size;