diff --git a/commands/i386/gas2ack/emit_ack.c b/commands/i386/gas2ack/emit_ack.c
index 585ad67e6..0dd878904 100644
--- a/commands/i386/gas2ack/emit_ack.c
+++ b/commands/i386/gas2ack/emit_ack.c
@@ -642,7 +642,7 @@ void ack_emit_instruction(asm86_t *a)
 		}
 		/* unsupported fnstsw */
 		if (a->opcode == FNSTSW) {
-			ack_printf(".data1 0xDF, 0xD0\n"); /* FNSTSW [eax] */
+			ack_printf(".data1 0xDF, 0xE0\n"); /* FNSTSW [eax] */
 			return;
 		}
 		/* unsupported frstor */