diff --git a/tools/tests/Makefile b/tools/tests/Makefile
index afa6578619..263caffb46 100644
--- a/tools/tests/Makefile
+++ b/tools/tests/Makefile
@@ -4,8 +4,6 @@ include $(XEN_ROOT)/tools/Rules.mk
 
 TARGET := test_x86_emulator
 
-HOSTCFLAGS += -D__TEST_HARNESS__
-
 .PHONY: all
 all: $(TARGET)
 
diff --git a/xen/arch/x86/x86_emulate.c b/xen/arch/x86/x86_emulate.c
index 7c28dd87b9..d13eb5689f 100644
--- a/xen/arch/x86/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate.c
@@ -6,7 +6,7 @@
  * Copyright (c) 2005 Keir Fraser
  */
 
-#ifdef __TEST_HARNESS__
+#ifndef __XEN__
 #include <stdio.h>
 #include <stdint.h>
 #include <public/xen.h>
@@ -1127,7 +1127,7 @@ x86_emulate_memop(
     return -1;
 }
 
-#ifndef __TEST_HARNESS__
+#ifdef __XEN__
 
 #include <asm/mm.h>
 #include <asm/uaccess.h>