From 4ea7bbc197de2af0938ff64423add33098ee7326 Mon Sep 17 00:00:00 2001
From: Roland Puntaier <puntaier@gtec.at>
Date: Tue, 28 Nov 2017 16:47:12 +0100
Subject: [PATCH] fix issue #2920

---
 _pytest/config.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/_pytest/config.py b/_pytest/config.py
index 1ae1ffd09..499c8079d 100644
--- a/_pytest/config.py
+++ b/_pytest/config.py
@@ -417,7 +417,7 @@ class PytestPluginManager(PluginManager):
         # _pytest prefix.
         assert isinstance(modname, (six.text_type, str)), "module name as text required, got %r" % modname
         modname = str(modname)
-        if self.get_plugin(modname) is not None:
+        if self.is_blocked(modname) or self.get_plugin(modname) is not None:
             return
         if modname in builtin_plugins:
             importspec = "_pytest." + modname