diff --git a/.gitignore b/.gitignore
index fb087f4..55124ee 100644
--- a/.gitignore
+++ b/.gitignore
@@ -56,3 +56,4 @@ gjs-0.7.1.tar.gz
 /gjs-1.46.0.tar.xz
 /gjs-1.47.0.tar.xz
 /gjs-1.47.4.tar.xz
+/gjs-1.47.90.tar.xz
diff --git a/gjs.spec b/gjs.spec
index fc2993a..0a022a1 100644
--- a/gjs.spec
+++ b/gjs.spec
@@ -1,8 +1,8 @@
 %global gobject_introspection_version 1.41.4
 
 Name:          gjs
-Version:       1.47.4
-Release:       2%{?dist}
+Version:       1.47.90
+Release:       1%{?dist}
 Summary:       Javascript Bindings for GNOME
 
 # The following files contain code from Mozilla which
@@ -21,7 +21,7 @@ BuildRequires: readline-devel
 BuildRequires: dbus-glib-devel
 BuildRequires: gtk3-devel
 BuildRequires: intltool
-BuildRequires: mozjs31-devel
+BuildRequires: mozjs38-devel
 BuildRequires: pkgconfig
 # Bootstrap requirements
 BuildRequires: gtk-doc gnome-common
@@ -93,6 +93,10 @@ find %{buildroot} -name '*.la' -exec rm -f {} ';'
 %{_datadir}/installed-tests
 
 %changelog
+* Wed Feb 15 2017 Kalev Lember <klember@redhat.com> - 1.47.90-1
+- Update to 1.47.90
+- Switch to building with mozjs38
+
 * Fri Feb 10 2017 Fedora Release Engineering <releng@fedoraproject.org> - 1.47.4-2
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_26_Mass_Rebuild
 
diff --git a/sources b/sources
index bd751b7..cd1f9f7 100644
--- a/sources
+++ b/sources
@@ -1 +1 @@
-SHA512 (gjs-1.47.4.tar.xz) = 9737328d3217b65d6309bf1dabb29ff57ba57c1337a3f00746e265651654630021148f4481b758a2623c7ca297009cfb48c6ae5d97b1ac4cb0ee92450b40ff02
+SHA512 (gjs-1.47.90.tar.xz) = a5a48a5c1f586ecc37c915ff971f910b8bc21c8602ddcce53daea5a9a2187ca7d605b648e807c2a5ab0aa91416e4a1e3bc8671ea41f0a71d4ce412816449128d