diff --git a/Makefile.in b/Makefile.in
index 3f44401dfe0484d5579b2151be35a2a0025c0558..ecff84dc4c00253db51f4d8583efc324e1dbb6fc 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -240,3 +240,4 @@ include $(CFG_SRC_DIR)/mk/snap.mk
 include $(CFG_SRC_DIR)/mk/clean.mk
 include $(CFG_SRC_DIR)/mk/autodep.mk
 include $(CFG_SRC_DIR)/mk/fuzzer.mk
+include $(CFG_SRC_DIR)/mk/pp.mk
diff --git a/mk/pp.mk b/mk/pp.mk
new file mode 100644
index 0000000000000000000000000000000000000000..a2aa77fe863fe61fd465a85a1f0c0ef018abd12a
--- /dev/null
+++ b/mk/pp.mk
@@ -0,0 +1,7 @@
+reformat: $(SREQ1)
+	@$(call E, reformat [stage1]: $@)
+	for i in $(wildcard $(addprefix $(S)src/comp/, \
+                          *.rs */*.rs */*/*.rs));  \
+    do $(call CFG_RUN_TARG,stage1, stage1/rustc$(X)) \
+       --pretty $$i >$$i.tmp && mv $$i.tmp $$i; \
+    done