diff --git a/doc/build.py b/doc/build.py
index 41964bb7..6a38cde2 100755
--- a/doc/build.py
+++ b/doc/build.py
@@ -31,7 +31,7 @@ def build_docs():
   if not '__version__' in dir(pip) or \
      LooseVersion(pip.__version__) < LooseVersion('1.5.4'):
     print("Updating pip")
-    check_call(['pip', 'install', '--upgrade', 'pip==1.5.4'])
+    check_call(['pip', 'install', '--upgrade', 'pip'])
   # Install Sphinx and Breathe.
   pip_install('sphinx-doc/sphinx',
               '4d2c17e043d9e8197fa5cd0db34212af3bb17069',