diff --git a/kern/trap.c b/kern/trap.c
index 8ed3fa8..88ca879 100644
--- a/kern/trap.c
+++ b/kern/trap.c
@@ -203,12 +203,13 @@ trap_dispatch(struct Trapframe *tf)
 		monitor(tf);
 		return;
 	} else if (tf->tf_trapno == T_SYSCALL) {
-		syscall(tf->tf_regs.reg_eax,
+		int32_t returned = syscall(tf->tf_regs.reg_eax,
 				tf->tf_regs.reg_edx,
 				tf->tf_regs.reg_ecx,
 				tf->tf_regs.reg_ebx,
 				tf->tf_regs.reg_edi,
 				tf->tf_regs.reg_esi);
+		tf->tf_regs.reg_eax = returned;
 		return;
 	}