diff --git a/model/map-jpa/src/main/java/org/keycloak/models/map/storage/jpa/user/entity/JpaUserEntity.java b/model/map-jpa/src/main/java/org/keycloak/models/map/storage/jpa/user/entity/JpaUserEntity.java
index e837e22a7c5..2142e7c0118 100644
--- a/model/map-jpa/src/main/java/org/keycloak/models/map/storage/jpa/user/entity/JpaUserEntity.java
+++ b/model/map-jpa/src/main/java/org/keycloak/models/map/storage/jpa/user/entity/JpaUserEntity.java
@@ -65,7 +65,8 @@ import static org.keycloak.models.map.storage.jpa.JpaMapStorageProviderFactory.C
 @Entity
 @Table(name = "kc_user",
         uniqueConstraints = {
-                @UniqueConstraint(columnNames = {"realmId", "username"}),
+                // if same username it can differ only in usernameWithCase
+                @UniqueConstraint(columnNames = {"realmId", "username", "usernameWithCase"}),
                 @UniqueConstraint(columnNames = {"realmId", "emailConstraint"})
         })
 @TypeDefs({@TypeDef(name = "jsonb", typeClass = JsonbType.class)})
diff --git a/model/map-jpa/src/main/resources/META-INF/users/jpa-users-changelog-2.xml b/model/map-jpa/src/main/resources/META-INF/users/jpa-users-changelog-2.xml
index a476f7fc74c..54d92d860e2 100644
--- a/model/map-jpa/src/main/resources/META-INF/users/jpa-users-changelog-2.xml
+++ b/model/map-jpa/src/main/resources/META-INF/users/jpa-users-changelog-2.xml
@@ -34,4 +34,9 @@ limitations under the License.
 
     </changeSet>
 
+    <changeSet author="keycloak" id="users-14797">
+        <addUniqueConstraint tableName="kc_user" columnNames="realmid, username, usernamewithcase"/>
+        <addUniqueConstraint tableName="kc_user" columnNames="realmid, emailconstraint"/>
+    </changeSet>
+
 </databaseChangeLog>