diff --git a/Network/HTTP/Conduit/Manager.hs b/Network/HTTP/Conduit/Manager.hs
--- a/Network/HTTP/Conduit/Manager.hs
+++ b/Network/HTTP/Conduit/Manager.hs
@@ -150,11 +150,19 @@
 -- | Create a 'Manager'. You must manually call 'closeManager' to shut it down.
 newManager :: ManagerSettings -> IO Manager
 newManager ms = do
-    certStore <- managerCertStore ms
+    icertStore <- I.newIORef Nothing
+    let getCertStore = do
+            mcertStore <- I.readIORef icertStore
+            case mcertStore of
+                Nothing -> do
+                    certStore <- managerCertStore ms
+                    I.writeIORef icertStore $ Just certStore
+                    return certStore
+                Just x -> return x
     mapRef <- I.newIORef (Just Map.empty)
     certCache <- I.newIORef Map.empty
     _ <- forkIO $ reap mapRef certCache
-    return $ Manager mapRef (managerConnCount ms) (managerCheckCerts ms $ certStore) certCache
+    return $ Manager mapRef (managerConnCount ms) (\x y -> getCertStore >>= \cs -> managerCheckCerts ms cs x y) certCache
 
 -- | Collect and destroy any stale connections.
 reap :: I.IORef (Maybe (Map.Map ConnKey (NonEmptyList ConnInfo)))
diff --git a/http-conduit.cabal b/http-conduit.cabal
--- a/http-conduit.cabal
+++ b/http-conduit.cabal
@@ -1,5 +1,5 @@
 name:            http-conduit
-version:         1.8.2
+version:         1.8.2.1
 license:         BSD3
 license-file:    LICENSE
 author:          Michael Snoyman <michael@snoyman.com>