Index: /trunk/src/VBox/Runtime/r0drv/darwin/the-darwin-kernel.h
===================================================================
--- /trunk/src/VBox/Runtime/r0drv/darwin/the-darwin-kernel.h	(revision 43380)
+++ /trunk/src/VBox/Runtime/r0drv/darwin/the-darwin-kernel.h	(revision 43381)
@@ -84,4 +84,10 @@
 # define AST_QUANTUM    UINT32_C(2)
 # define AST_URGENT     UINT32_C(4)
+#endif
+
+/* This flag was added in 10.6, it seems.  Should be harmless in earlier
+   releases... */
+#if MAC_OS_X_VERSION_MIN_REQUIRED < 1060
+# define kIOMemoryMapperNone UINT32_C(0x800)
 #endif