Index: libcfa/src/concurrency/kernel/startup.cfa
===================================================================
--- libcfa/src/concurrency/kernel/startup.cfa	(revision 19de7864a47b37585af2cc6f6108a0337c2a37c1)
+++ libcfa/src/concurrency/kernel/startup.cfa	(revision 68a867eecb31283fe4097c3cc2eb6c0a5f23b188)
@@ -118,4 +118,5 @@
 
 extern size_t __page_size;
+extern int __map_prot;
 
 //-----------------------------------------------------------------------------
@@ -725,4 +726,10 @@
 		}
 	#else
+		__cfaabi_dbg_debug_do(
+			// pthread has no mechanism to create the guard page in user supplied stack.
+			if ( mprotect( stack, __page_size, __map_prot ) == -1 ) {
+				abort( "mprotect : internal error, mprotect failure, error(%d) %s.", errno, strerror( errno ) );
+			} // if
+		);
 		free( stack );
 	#endif