Index: kernel/arch/amd64/src/syscall.c
===================================================================
--- kernel/arch/amd64/src/syscall.c	(revision e13daa5d4c1573540f85ba102446af543f3d2c72)
+++ kernel/arch/amd64/src/syscall.c	(revision 246f939e5a6aa9f58ef53bebdf4fb6079351f238)
@@ -66,6 +66,7 @@
 	 * - clear DF so that the string instructions operate in
 	 *   the right direction
+	 * - clear NT to prevent a #GP should the flag proliferate to an IRET
 	 */
-	write_msr(AMD_MSR_SFMASK, RFLAGS_IF | RFLAGS_DF);
+	write_msr(AMD_MSR_SFMASK, RFLAGS_IF | RFLAGS_DF | RFLAGS_NT);
 }