diff --git a/src/cpu/core_full/op.h b/src/cpu/core_full/op.h
index b2800dcf..e2c7426e 100644
--- a/src/cpu/core_full/op.h
+++ b/src/cpu/core_full/op.h
@@ -316,10 +316,10 @@ switch (inst.code.op) {
 		if (--reg_cx) break;
 		goto nextopcode;
 	case O_LOOPZ:
-		if (--reg_cx && !get_ZF()) break;
+		if (--reg_cx && get_ZF()) break;
 		goto nextopcode;
 	case O_LOOPNZ:
-		if (--reg_cx && get_ZF()) break;
+		if (--reg_cx && !get_ZF()) break;
 		goto nextopcode;
 	case O_JCXZ:
 		if (reg_cx) goto nextopcode;