diff --git a/Formula/python3.rb b/Formula/python3.rb
index 8f0cdadf14..880b67eab0 100644
--- a/Formula/python3.rb
+++ b/Formula/python3.rb
@@ -3,6 +3,7 @@ class Python3 < Formula
   homepage "https://www.python.org/"
   url "https://www.python.org/ftp/python/3.6.4/Python-3.6.4.tar.xz"
   sha256 "159b932bf56aeaa76fd66e7420522d8c8853d486b8567c459b84fe2ed13bcaba"
+  revision 1
   head "https://github.com/python/cpython", :using => :git
 
   bottle do
@@ -357,6 +358,7 @@ class Python3 < Formula
     system "#{bin}/python#{xy}", "-c", "import sqlite3"
     # Check if some other modules import. Then the linked libs are working.
     system "#{bin}/python#{xy}", "-c", "import tkinter; root = tkinter.Tk()"
+    system "#{bin}/python#{xy}", "-c", "import _gdbm"
     system bin/"pip3", "list"
   end
 end