Index: kernel/generic/src/main/uinit.c
===================================================================
--- kernel/generic/src/main/uinit.c	(revision 98000fb4ea6015506f059c9b121e417ce991ecfd)
+++ kernel/generic/src/main/uinit.c	(revision 716fb9d713ceb210b9824bd965bbd54b4a054b9f)
@@ -80,4 +80,12 @@
 
 	free((uspace_arg_t *) arg);
+	
+	/*
+	 * Disable interrupts so that the execution of userspace() is not
+	 * disturbed by any interrupts as some of the userspace()
+	 * implementations will switch to the userspace stack before switching
+	 * the mode.
+	 */
+	(void) interrupts_disable();
 	userspace(&uarg);
 }