diff --git a/src/main/java/caosdb/server/accessControl/UserSources.java b/src/main/java/caosdb/server/accessControl/UserSources.java
index a3f35c11b0f3bcc10e67397bd8c48c6e969fcc7d..d0f707ebaaec8aa97e9b87d760fc0631cbd2f72a 100644
--- a/src/main/java/caosdb/server/accessControl/UserSources.java
+++ b/src/main/java/caosdb/server/accessControl/UserSources.java
@@ -31,6 +31,7 @@ import caosdb.server.utils.ServerMessages;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.lang.reflect.InvocationTargetException;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Set;
@@ -72,12 +73,14 @@ public class UserSources extends HashMap<String, UserSource> {
             @SuppressWarnings("unchecked")
             final Class<? extends UserSource> clazz =
                 (Class<? extends UserSource>) Class.forName(className);
-            this.put(clazz.newInstance());
-          } catch (final ClassNotFoundException e) {
-            logger.error("LOAD_USER_SOURCE", e);
-          } catch (final InstantiationException e) {
-            logger.error("LOAD_USER_SOURCE", e);
-          } catch (final IllegalAccessException e) {
+            this.put(clazz.getDeclaredConstructor().newInstance());
+          } catch (IllegalArgumentException
+              | InvocationTargetException
+              | NoSuchMethodException
+              | SecurityException
+              | ClassNotFoundException
+              | InstantiationException
+              | IllegalAccessException e) {
             logger.error("LOAD_USER_SOURCE", e);
           }
         }