diff --git a/plugins/proto-interface/src/main/java/org/polypheny/db/protointerface/ClientManager.java b/plugins/proto-interface/src/main/java/org/polypheny/db/protointerface/ClientManager.java
index 18a8d24dde..426cdc56e3 100644
--- a/plugins/proto-interface/src/main/java/org/polypheny/db/protointerface/ClientManager.java
+++ b/plugins/proto-interface/src/main/java/org/polypheny/db/protointerface/ClientManager.java
@@ -76,28 +76,40 @@ public void unregisterConnection( PIClient client ) {
     }
 
 
-    public String registerConnection( ConnectionRequest connectionRequest, Transport t ) throws AuthenticationException, TransactionException, PIServiceException {
-        byte[] raw = new byte[32];
-        new SecureRandom().nextBytes( raw );
-        String uuid = Base64.getUrlEncoder().encodeToString( raw );
-
-        if ( log.isTraceEnabled() ) {
-            log.trace( "User {} tries to establish connection via proto interface.", uuid );
-        }
-        final LogicalUser user;
+    public LogicalUser getUser( ConnectionRequest connectionRequest, Transport t ) throws AuthenticationException {
         if ( connectionRequest.hasUsername() ) {
             String username = connectionRequest.getUsername();
             if ( !connectionRequest.hasPassword() ) {
                 throw new AuthenticationException( "A password is required" );
             }
             String password = connectionRequest.getPassword();
-            user = authenticator.authenticate( username, password );
-        } else {
-            user = t.getPeer()
-                    .flatMap( u -> Catalog.getInstance().getSnapshot().getUser( u ) )
-                    .orElseThrow( () -> new AuthenticationException( "Peer authentication failed: No user with that name" ) );
+            return authenticator.authenticate( username, password );
+        } else if ( t.getPeer().isPresent() ) {
+            String username = t.getPeer().get();
+            Optional<LogicalUser> catalogUser = Catalog.getInstance().getSnapshot().getUser( username );
+            if ( catalogUser.isPresent() ) {
+                return catalogUser.get();
+            } else {
+                if ( username.equals( System.getProperty( "user.name" ) ) ) {
+                    return Catalog.getInstance().getSnapshot().getUser( Catalog.USER_NAME ).orElseThrow();
+                } else {
+                    throw new AuthenticationException( "Peer authentication failed: No user with that name" );
+                }
+            }
         }
+        throw new AuthenticationException( "Authentication failed" );
+    }
 
+
+    public String registerConnection( ConnectionRequest connectionRequest, Transport t ) throws AuthenticationException, TransactionException, PIServiceException {
+        byte[] raw = new byte[32];
+        new SecureRandom().nextBytes( raw );
+        String uuid = Base64.getUrlEncoder().encodeToString( raw );
+
+        if ( log.isTraceEnabled() ) {
+            log.trace( "User {} tries to establish connection via proto interface.", uuid );
+        }
+        final LogicalUser user = getUser( connectionRequest, t );
         Transaction transaction = transactionManager.startTransaction( user.id, false, "proto-interface" );
         transaction.commit();
         LogicalNamespace namespace = getNamespaceOrDefault( connectionRequest );
@@ -122,6 +134,7 @@ public Stream<Entry<String, PIClient>> getClients() {
         return clients.entrySet().stream();
     }
 
+
     public int getClientCount() {
         return clients.size();
     }