diff --git a/src/main/java/com/faendir/acra/model/User.java b/src/main/java/com/faendir/acra/model/User.java
index 0d4393d..0b07673 100644
--- a/src/main/java/com/faendir/acra/model/User.java
+++ b/src/main/java/com/faendir/acra/model/User.java
@@ -13,7 +13,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-
 package com.faendir.acra.model;
 
 import org.springframework.data.annotation.PersistenceConstructor;
@@ -21,6 +20,7 @@ import org.springframework.lang.NonNull;
 import org.springframework.security.core.GrantedAuthority;
 import org.springframework.security.core.userdetails.UserDetails;
 
+import javax.persistence.Column;
 import javax.persistence.ElementCollection;
 import javax.persistence.Entity;
 import javax.persistence.EnumType;
@@ -41,8 +41,12 @@ import java.util.stream.Stream;
 public class User implements UserDetails {
     @Id private String username;
     @Enumerated(EnumType.STRING)
-    @ElementCollection(fetch = FetchType.EAGER) private Set<Role> roles;
-    @ElementCollection(fetch = FetchType.EAGER) private Set<Permission> permissions;
+    @Column(nullable = false)
+    @ElementCollection(fetch = FetchType.EAGER)
+    private Set<Role> roles;
+    @Column(nullable = false)
+    @ElementCollection(fetch = FetchType.EAGER)
+    private Set<Permission> permissions;
     private String password;
 
     @PersistenceConstructor
diff --git a/src/main/java/com/faendir/acra/ui/view/user/UserManagerView.java b/src/main/java/com/faendir/acra/ui/view/user/UserManagerView.java
index 005a57a..9be6019 100644
--- a/src/main/java/com/faendir/acra/ui/view/user/UserManagerView.java
+++ b/src/main/java/com/faendir/acra/ui/view/user/UserManagerView.java
@@ -91,7 +91,10 @@ public class UserManagerView extends BaseView {
                 ComboBox<Permission.Level> levelComboBox = new ComboBox<>(null, Arrays.asList(Permission.Level.values()));
                 levelComboBox.setEmptySelectionAllowed(false);
                 levelComboBox.setValue(permission);
-                levelComboBox.addValueChangeListener(e -> userService.setPermission(user, app, e.getValue()));
+                levelComboBox.addValueChangeListener(e -> {
+                    userService.setPermission(user, app, e.getValue());
+                    userGrid.getDataProvider().refreshAll();
+                });
                 return levelComboBox;
             }, new ComponentRenderer(), Messages.ACCESS_PERMISSION, app.getName());
         }
diff --git a/src/main/resources/db/changelog/db.changelog-master.yaml b/src/main/resources/db/changelog/db.changelog-master.yaml
index 12af56a..2e1a640 100644
--- a/src/main/resources/db/changelog/db.changelog-master.yaml
+++ b/src/main/resources/db/changelog/db.changelog-master.yaml
@@ -616,4 +616,12 @@ databaseChangeLog:
             type: INT
             constraints:
               nullable: false
+- changeSet:
+    id: 2018-08-24-fix-permission-key
+    author: lukas
+    changes:
+    - addPrimaryKey:
+        columnNames: user_username, app_id
+        tableName: user_permissions
+        constraintName: PK_user_permissions