diff --git a/rdoc.gemspec b/rdoc.gemspec
index 47f48023fc..c3752c9159 100644
--- a/rdoc.gemspec
+++ b/rdoc.gemspec
@@ -51,9 +51,10 @@ RDoc includes the +rdoc+ and +ri+ tools for generating and displaying documentat
     "exe/rdoc",
     "exe/ri",
     "man/ri.1",
+    "rdoc.gemspec",
   ]
   template_files = Dir.glob("lib/rdoc/generator/template/**/*")
-  lib_files = Dir.glob("lib/**/*.{rb,kpeg,ry}")
+  lib_files = Dir.glob("lib/**/*.{rb,kpeg,ry}", base: File.expand_path('..', __FILE__))
 
   s.files = (non_lib_files + template_files + lib_files).uniq