diff --git a/MasterPassword/Java/masterpassword-gui/src/main/java/com/lyndir/masterpassword/gui/ModelUser.java b/MasterPassword/Java/masterpassword-gui/src/main/java/com/lyndir/masterpassword/gui/ModelUser.java
index 3dbca406..45d5133d 100644
--- a/MasterPassword/Java/masterpassword-gui/src/main/java/com/lyndir/masterpassword/gui/ModelUser.java
+++ b/MasterPassword/Java/masterpassword-gui/src/main/java/com/lyndir/masterpassword/gui/ModelUser.java
@@ -58,12 +58,19 @@ public class ModelUser extends User {
         if (!model.hasKeyID()) {
             model.setKeyID( key.getKeyID() );
             MPUserFileManager.get().save();
-        } else if (!model.hasKeyID( key.getKeyID() ))
+        } else if (!model.hasKeyID( key.getKeyID() )) {
+            reset();
             throw new MasterKeyException( strf( "Incorrect master password for user: %s", getFullName() ) );
+        }
 
         return key;
     }
 
+    @Override
+    public void reset() {
+        masterPassword = null;
+    }
+
     @Override
     public Iterable<Site> findSitesByName(final String query) {
         return FluentIterable.from( model.findSitesByName( query ) ).transform( new Function<MPSiteResult, Site>() {
diff --git a/MasterPassword/Java/masterpassword-gui/src/main/java/com/lyndir/masterpassword/gui/User.java b/MasterPassword/Java/masterpassword-gui/src/main/java/com/lyndir/masterpassword/gui/User.java
index 4c8573a1..4720ae1d 100644
--- a/MasterPassword/Java/masterpassword-gui/src/main/java/com/lyndir/masterpassword/gui/User.java
+++ b/MasterPassword/Java/masterpassword-gui/src/main/java/com/lyndir/masterpassword/gui/User.java
@@ -32,14 +32,22 @@ public abstract class User {
     @Nonnull
     public MasterKey getKey() throws MasterKeyException {
         if (key == null) {
-            if (!hasKey())
+            String masterPassword = getMasterPassword();
+            if (masterPassword == null || masterPassword.isEmpty()) {
+                reset();
                 throw new MasterKeyException( strf( "Master password unknown for user: %s", getFullName() ) );
-            key = new MasterKey( getFullName(), getMasterPassword() );
+            }
+
+            key = new MasterKey( getFullName(), masterPassword );
         }
 
         return key;
     }
 
+    public void reset() {
+        key = null;
+    }
+
     public abstract Iterable<Site> findSitesByName(final String siteName);
 
     public abstract void addSite(final Site site);