diff --git a/tools/tests/x86_emulator/Makefile b/tools/tests/x86_emulator/Makefile
index e18725d0c3..5003c464f3 100644
--- a/tools/tests/x86_emulator/Makefile
+++ b/tools/tests/x86_emulator/Makefile
@@ -297,6 +297,11 @@ x86_emulate:
 
 HOSTCFLAGS-x86_64 := -fno-PIE
 $(call cc-option-add,HOSTCFLAGS-x86_64,HOSTCC,-no-pie)
+
+# clang's integrated as does not support some mnemonics:
+#  https://github.com/llvm/llvm-project/issues/183635
+$(call cc-option-add,HOSTCFLAGS-x86_64,HOSTCC,-no-integrated-as)
+
 HOSTCFLAGS += $(CFLAGS_xeninclude) -I. $(HOSTCFLAGS-$(XEN_COMPILE_ARCH))
 
 x86.h := $(addprefix $(XEN_ROOT)/tools/include/xen/asm/,\