diff --git a/libgcc/ChangeLog b/libgcc/ChangeLog
index 863339119ac..363ecc2fa73 100644
--- a/libgcc/ChangeLog
+++ b/libgcc/ChangeLog
@@ -1,3 +1,9 @@
+2011-08-12  Paolo Bonzini  <bonzini@gnu.org>
+
+	PR bootstrap/50047
+	* Makefile.in (install-unwind_h): Create
+	$(gcc_objdir)/include/unwind.h atomically.
+
 2011-08-11  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
 
 	* Makefile.in (install-unwind_h): Remove destination file first.
diff --git a/libgcc/Makefile.in b/libgcc/Makefile.in
index a2cb7c70713..e9f2fa2f2b8 100644
--- a/libgcc/Makefile.in
+++ b/libgcc/Makefile.in
@@ -991,9 +991,10 @@ gcc-extra-parts:
 all: $(extra-parts)
 
 install-unwind_h:
-	rm -f $(gcc_objdir)/include/unwind.h
-	cp unwind.h $(gcc_objdir)/include/unwind.h
-	chmod a+r $(gcc_objdir)/include/unwind.h
+	dest=$(gcc_objdir)/include/tmp$$$$-unwind.h; \
+	cp unwind.h $$dest; \
+	chmod a+r $$dest; \
+	sh $(srcdir)/../move-if-change $$dest $(gcc_objdir)/include/unwind.h
 
 all: install-unwind_h