diff --git a/Makefile.pre.in b/Makefile.pre.in
--- a/Makefile.pre.in
+++ b/Makefile.pre.in
@@ -715,6 +715,7 @@
 Programs/_freeze_importlib: Programs/_freeze_importlib.o $(LIBRARY_OBJS_OMIT_FROZEN)
 	$(LINKCC) $(PY_LDFLAGS) -o $@ Programs/_freeze_importlib.o $(LIBRARY_OBJS_OMIT_FROZEN) $(LIBS) $(MODLIBS) $(SYSLIBS) $(LDLAST)
 
+ifeq ($(findstring _PYTHON_HOST_PLATFORM, $(PYTHON_FOR_BUILD)), )
 Python/importlib_external.h: $(srcdir)/Lib/importlib/_bootstrap_external.py Programs/_freeze_importlib
 	./Programs/_freeze_importlib \
 		$(srcdir)/Lib/importlib/_bootstrap_external.py Python/importlib_external.h
@@ -722,6 +723,10 @@
 Python/importlib.h: $(srcdir)/Lib/importlib/_bootstrap.py Programs/_freeze_importlib
 	./Programs/_freeze_importlib \
 		$(srcdir)/Lib/importlib/_bootstrap.py Python/importlib.h
+else
+Python/importlib_external.h:
+Python/importlib.h:
+endif
 
 
 ############################################################################
@@ -781,11 +786,15 @@
 
 $(IO_OBJS): $(IO_H)
 
+ifeq ($(findstring _PYTHON_HOST_PLATFORM, $(PYTHON_FOR_BUILD)), )
 $(GRAMMAR_H): $(GRAMMAR_INPUT) $(PGEN)
 		@$(MKDIR_P) Include
 		$(PGEN) $(GRAMMAR_INPUT) $(GRAMMAR_H) $(GRAMMAR_C)
 $(GRAMMAR_C): $(GRAMMAR_H)
 		touch $(GRAMMAR_C)
+else
+$(GRAMMAR_H):
+endif
 
 $(PGEN): $(PGENOBJS)
 		$(CC) $(OPT) $(PY_LDFLAGS) $(PGENOBJS) $(LIBS) -o $(PGEN)