diff --git a/changelog.html b/changelog.html
index f9713fda7c2a8395319b519d99684cf316a81008..06e69f3ff4c1d584de8c6816fca287015686d338 100644
--- a/changelog.html
+++ b/changelog.html
@@ -79,6 +79,9 @@ Upcoming changes</a>
   <li class="rfe">
     Show displayName in build remote API.
     (<a href="https://issues.jenkins-ci.org/browse/JENKINS-26723">issue 26723</a>)
+  <li class=rfe>
+    Added a switch (<tt>-Dhudson.model.User.allowNonExistentUserToLogin=true</tt>) to let users login even when the record is not found in the backend security realm.
+    (<a href="https://issues.jenkins-ci.org/browse/JENKINS-22346">issue 22346</a>)
 </ul>
 <h3><a name=v1.601>What's new in 1.601</a> (2015/03/03)</h3>
 <ul class=image>
diff --git a/core/src/main/java/hudson/model/User.java b/core/src/main/java/hudson/model/User.java
index d39b9b6f9d605d2ab5e17d394a6d13c3ccf33825..1ef3af9989b84f1fa58e33d6ce30c48fd4d3c3ae 100644
--- a/core/src/main/java/hudson/model/User.java
+++ b/core/src/main/java/hudson/model/User.java
@@ -304,7 +304,8 @@ public class User extends AbstractModelObject implements AccessControlled, Descr
             // backend can't load information about other users. so use the stored information if available
         } catch (UsernameNotFoundException e) {
             // if the user no longer exists in the backend, we need to refuse impersonating this user
-            throw e;
+            if (!ALLOW_NON_EXISTENT_USER_TO_LOGIN)
+                throw e;
         } catch (DataAccessException e) {
             // seems like it's in the same boat as UserMayOrMayNotExistException
         }
@@ -976,5 +977,15 @@ public class User extends AbstractModelObject implements AccessControlled, Descr
         }
     }
 
+    /**
+     * Jenkins now refuses to let the user login if he/she doesn't exist in {@link SecurityRealm},
+     * which was necessary to make sure users removed from the backend will get removed from the frontend.
+     * <p>
+     * Unfortunately this infringed some legitimate use cases of creating Jenkins-local users for
+     * automation purposes. This escape hatch switch can be enabled to resurrect that behaviour.
+     *
+     * JENKINS-22346.
+     */
+    public static boolean ALLOW_NON_EXISTENT_USER_TO_LOGIN = Boolean.getBoolean(User.class.getName()+".allowNonExistentUserToLogin");
 }