diff --git a/.gitignore b/.gitignore
index 0a6f723..a87add1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 /libcxxabi-3.9.0.src.tar.xz
+/libcxxabi-4.0.0.src.tar.xz
diff --git a/libcxxabi.spec b/libcxxabi.spec
index d01c3f9..cd0de4b 100644
--- a/libcxxabi.spec
+++ b/libcxxabi.spec
@@ -1,5 +1,5 @@
 Name:		libcxxabi
-Version:	3.9.0
+Version:	4.0.0
 Release:	1%{?dist}
 Summary:	Low level support for a standard C++ library
 License:	MIT or NCSA
@@ -88,6 +88,9 @@ cp -a include/* %{buildroot}%{_includedir}
 %{_libdir}/libc++abi.a
 
 %changelog
+* Sat Apr 22 2017 Tom Callaway <spot@fedoraproject.org> - 4.0.0-1
+- update to 4.0.0
+
 * Mon Feb 20 2017 Tom Callaway <spot@fedoraproject.org> - 3.9.0-1
 - update to 3.9.0
 - apply fixes from libcxx
diff --git a/sources b/sources
index 396523b..7244c2d 100644
--- a/sources
+++ b/sources
@@ -1 +1 @@
-SHA512 (libcxxabi-3.9.0.src.tar.xz) = 500207bfd59664bd42d920741d6b467c4b88569453742db6470af081c77be04894e097a14b8419e333b51abce484566366e35cbc3ed2607cd86dfc0ec0ddd0c5
+SHA512 (libcxxabi-4.0.0.src.tar.xz) = b69933a0bde00321323e98962cd54b78a48bc5e93448d7a5124cb5ef844497ba7648cd92fcbe476186c60c7742e3121841f150c142c2a14c1bf2aa26a8b93d64