diff --git a/xen/Rules.mk b/xen/Rules.mk
index ceb3d204b8..d65d6a4899 100644
--- a/xen/Rules.mk
+++ b/xen/Rules.mk
@@ -227,8 +227,8 @@ cmd_cpp_i_c = $(CPP) $(filter-out -Wa$(comma)%,$(c_flags)) -MQ $@ -o $@ $<
 quiet_cmd_cc_s_c = CC      $@
 cmd_cc_s_c = $(CC) $(filter-out -Wa$(comma)%,$(c_flags)) -S $< -o $@
 
-quiet_cmd_s_S = CPP     $@
-cmd_s_S = $(CPP) $(filter-out -Wa$(comma)%,$(a_flags)) -MQ $@ -o $@ $<
+quiet_cmd_cpp_s_S = CPP     $@
+cmd_cpp_s_S = $(CPP) $(filter-out -Wa$(comma)%,$(a_flags)) -MQ $@ -o $@ $<
 
 %.i: %.c FORCE
 	$(call if_changed,cpp_i_c)