diff --git a/tools/include/xen-foreign/Makefile b/tools/include/xen-foreign/Makefile
index bb09c93915..270a9752ca 100644
--- a/tools/include/xen-foreign/Makefile
+++ b/tools/include/xen-foreign/Makefile
@@ -36,8 +36,9 @@ x86_32.h: mkheader.py structs.py $(ROOT)/arch-x86/xen-x86_32.h $(ROOT)/arch-x86/
 x86_64.h: mkheader.py structs.py $(ROOT)/arch-x86/xen-x86_64.h $(ROOT)/arch-x86/xen.h $(ROOT)/xen.h
 	$(PYTHON) $< $* $@.tmp $(filter %.h,$^)
 	#Avoid mixing an alignment directive with a uint64_t cast or sizeof expression
-	sed 's/(__align8__ \(u\?int64_t\))/(\1)/g' -i $@.tmp
-	$(call move-if-changed,$@.tmp,$@)
+	sed 's/(__align8__ \(u\?int64_t\))/(\1)/g' < $@.tmp > $@.tmp2
+	rm $@.tmp
+	$(call move-if-changed,$@.tmp2,$@)
 
 checker.c: mkchecker.py structs.py
 	$(PYTHON) $< $@ $(architectures)