diff --git a/office/taskjuggler/taskjuggler.SlackBuild b/office/taskjuggler/taskjuggler.SlackBuild
index a54787360c..1f1890151b 100644
--- a/office/taskjuggler/taskjuggler.SlackBuild
+++ b/office/taskjuggler/taskjuggler.SlackBuild
@@ -71,12 +71,12 @@ printf("%s/%s/gems/%s\n",
 
 gem specification $CWD/$PRGNAM-$VERSION.gem | \
 	ruby -r yaml -r rbconfig -e '
-c = Config::CONFIG
+c = RbConfig::CONFIG
 path = sprintf("%s/%s/gems/%s",
         c["libdir"],
         c["RUBY_INSTALL_NAME"],
         c["ruby_version"])
-sys_gemspecs = Dir.glob(path + "/specifications/*").map {|g| gs = Gem::Specification.load(g); gs.name }
+sys_gemspecs = Dir.glob(path + "/specifications/**/*.gemspec").map {|g| gs = Gem::Specification.load(g); gs.name }
 obj = Gem::Specification.from_yaml($stdin)
 obj.dependencies.each {|dep|
         if not(dep.type == :runtime)