diff --git a/src/vm.c b/src/vm.c
index 9f21eb7..95e1f0a 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -917,7 +917,7 @@ static enum opcode execute_instruction(enum opcode opcode)
 		scenario_call(stack_pop().i);
 		break;
 	}
-	case MSG: {
+	case _MSG: {
 		if (config.echo)
 			echo_message(get_argument(0));
 		if (ain->msgf < 0)
@@ -925,7 +925,7 @@ static enum opcode execute_instruction(enum opcode opcode)
 		stack_push(get_argument(0));
 		stack_push(ain->nr_messages);
 		stack_push_string(string_ref(ain->messages[get_argument(0)]));
-		function_call(ain->msgf, instr_ptr + instruction_width(MSG));
+		function_call(ain->msgf, instr_ptr + instruction_width(_MSG));
 		break;
 	}
 	case JUMP: { // ADDR
diff --git a/subprojects/libsys4 b/subprojects/libsys4
index 742ccb7..5468eed 160000
--- a/subprojects/libsys4
+++ b/subprojects/libsys4
@@ -1 +1 @@
-Subproject commit 742ccb701095d83c6cf324d67f1e2c1d91dd7554
+Subproject commit 5468eed9ba1c3e93da2891040229952c0ef356d3