diff -r 470954641f3b Makefile.pre.in
--- a/Makefile.pre.in	Sun Jun 05 12:07:48 2016 +0000
+++ b/Makefile.pre.in	Sun Jun 05 23:46:40 2016 +0200
@@ -793,13 +793,15 @@
 	if test "$(cross_compiling)" != "yes"; then \
 		$(PGEN) $(GRAMMAR_INPUT) $(GRAMMAR_H) $(GRAMMAR_C); \
 	else \
-		cp $(srcdir)/Include/graminit.h $(GRAMMAR_H); \
+		cp $(srcdir)/Include/graminit.h $(GRAMMAR_H).tmp; \
+		mv $(GRAMMAR_H).tmp $(GRAMMAR_H); \
 	fi
 $(GRAMMAR_C): $(GRAMMAR_H)
 	if test "$(cross_compiling)" != "yes"; then \
 		touch $(GRAMMAR_C); \
 	else \
-		cp $(srcdir)/Python/graminit.c $(GRAMMAR_C); \
+		cp $(srcdir)/Python/graminit.c $(GRAMMAR_C).tmp; \
+		mv $(GRAMMAR_C).tmp $(GRAMMAR_C); \
 	fi
 
 $(PGEN): $(PGENOBJS)