diff --git a/rubygem-gobject-introspection.spec b/rubygem-gobject-introspection.spec
index ec21714..44dd9b5 100644
--- a/rubygem-gobject-introspection.spec
+++ b/rubygem-gobject-introspection.spec
@@ -53,13 +53,8 @@ BuildArch:	noarch
 Documentation for %{name}
 
 %prep
-%setup -q -c -T
-TOPDIR=$(pwd)
-mkdir tmpunpackdir
-pushd tmpunpackdir
-
-gem unpack %{SOURCE0}
-cd %{gem_name}-%{version}
+%setup -q -n %{gem_name}-%{version}
+mv ../%{gem_name}-%{version}.gemspec .
 
 # Patches
 
@@ -70,17 +65,10 @@ gem specification -l --ruby %{SOURCE0} > %{gem_name}.gemspec
 # Allow ruby-gnome2 no less than ones
 sed -i -e 's|= 3\.4\.9|>= 3.4.9|' %{gem_name}.gemspec
 
-gem build %{gem_name}.gemspec
-mv %{gem_name}-%{version}.gem $TOPDIR
-
-popd
-rm -rf tmpunpackdir
-
 %build
-mkdir -p .%{gem_dir}
-
 export CONFIGURE_ARGS="--with-cflags='%{optflags} -Werror-implicit-function-declaration'"
 export CONFIGURE_ARGS="$CONFIGURE_ARGS --with-pkg-config-dir=$(pwd)%{_libdir}/pkgconfig"
+gem build %{gem_name}-%{version}.gemspec
 %gem_install
 
 %install