Implement PEP 393.
diff --git a/Makefile.pre.in b/Makefile.pre.in
index d2546eb..6123946 100644
--- a/Makefile.pre.in
+++ b/Makefile.pre.in
@@ -629,7 +629,6 @@
 		$(srcdir)/Objects/stringlib/partition.h \
 		$(srcdir)/Objects/stringlib/split.h \
 		$(srcdir)/Objects/stringlib/stringdefs.h \
-		$(srcdir)/Objects/stringlib/string_format.h \
 		$(srcdir)/Objects/stringlib/transmogrify.h \
 		$(srcdir)/Objects/stringlib/unicodedefs.h \
 		$(srcdir)/Objects/stringlib/localeutil.h
@@ -639,7 +638,7 @@
 Objects/bytearrayobject.o: $(srcdir)/Objects/bytearrayobject.c $(BYTESTR_DEPS)
 
 Objects/unicodeobject.o: $(srcdir)/Objects/unicodeobject.c \
-				$(BYTESTR_DEPS)
+				$(BYTESTR_DEPS) $(srcdir)/Objects/stringlib/unicode_format.h
 
 Objects/dictobject.o: $(srcdir)/Objects/stringlib/eq.h
 Objects/setobject.o: $(srcdir)/Objects/stringlib/eq.h
@@ -650,8 +649,7 @@
 Python/ceval.o: $(OPCODETARGETS_H) Python/ceval_gil.h
 
 Python/formatter_unicode.o: $(srcdir)/Python/formatter_unicode.c \
-				$(BYTESTR_DEPS) \
-				$(srcdir)/Objects/stringlib/formatter.h
+				$(BYTESTR_DEPS)
 
 Objects/typeobject.o: $(srcdir)/Objects/typeslots.inc
 $(srcdir)/Objects/typeslots.inc: $(srcdir)/Include/typeslots.h $(srcdir)/Objects/typeslots.py