diff --git a/src/layman/util.py b/src/layman/util.py
index d21f08136..182c132af 100644
--- a/src/layman/util.py
+++ b/src/layman/util.py
@@ -277,7 +277,7 @@ def call_modules_fn(modules, fn_name, args=None, kwargs=None, omit_duplicate_cal
 DUMB_MAP_ADAPTER_DICT = {}
 
 
-def url_for(endpoint, *, internal=False, x_forwarded_prefix=None, **values):
+def _url_for(endpoint, *, server_name, proxy_server_name, internal=False, x_forwarded_prefix=None, **values):
     assert not (internal and values.get('_external'))
     assert not (internal and x_forwarded_prefix)
     x_forwarded_prefix = x_forwarded_prefix or ''
@@ -285,21 +285,28 @@ def url_for(endpoint, *, internal=False, x_forwarded_prefix=None, **values):
     assert (current_app.config.get('SERVER_NAME', None) is not None) == (current_app.config['TESTING'] is True)
     # Flask does not accept SERVER_NAME without dot, and without SERVER_NAME url_for cannot be used
     # therefore DUMB_MAP_ADAPTER_DICT is created manually ...
-    dumb_map_adapter = DUMB_MAP_ADAPTER_DICT.get(x_forwarded_prefix)
+    dict_key = f"{proxy_server_name} {x_forwarded_prefix}"
+    dumb_map_adapter = DUMB_MAP_ADAPTER_DICT.get(dict_key)
     if dumb_map_adapter is None:
         dumb_map_adapter = current_app.url_map.bind(
-            settings.LAYMAN_PROXY_SERVER_NAME + x_forwarded_prefix,
+            proxy_server_name + x_forwarded_prefix,
             url_scheme=current_app.config['PREFERRED_URL_SCHEME']
         )
-        DUMB_MAP_ADAPTER_DICT[x_forwarded_prefix] = dumb_map_adapter
+        DUMB_MAP_ADAPTER_DICT[dict_key] = dumb_map_adapter
     result = dumb_map_adapter.build(endpoint, values=values, force_external=True)
     if internal:
         _, netloc, path, query, fragment = urllib.parse.urlsplit(result)
-        netloc = settings.LAYMAN_SERVER_NAME
+        netloc = server_name
         result = urllib.parse.urlunsplit(('http', netloc, path, query, fragment))
     return result
 
 
+def url_for(endpoint, *, internal=False, x_forwarded_prefix=None, **values):
+    return _url_for(endpoint, server_name=settings.LAYMAN_SERVER_NAME,
+                    proxy_server_name=settings.LAYMAN_PROXY_SERVER_NAME,
+                    internal=internal, x_forwarded_prefix=x_forwarded_prefix, **values)
+
+
 def get_internal_sources(publ_type):
     return get_modules_from_names(get_publication_types()[publ_type]['internal_sources'])
 
diff --git a/src/layman/util_test.py b/src/layman/util_test.py
index 438d0754f..3535f809c 100644
--- a/src/layman/util_test.py
+++ b/src/layman/util_test.py
@@ -117,3 +117,20 @@ def test_publication_interface_methods():
 def test_url_for(endpoint, internal, params, expected_url):
     with app.app_context():
         assert util.url_for(endpoint, internal=internal, **params) == expected_url
+
+
+@pytest.mark.parametrize('endpoint, internal, params, expected_url', [
+    ('rest_workspace_maps.get', False, {'workspace': 'workspace_name'},
+     f'http://enjoychallenge.tech/rest/{settings.REST_WORKSPACES_PREFIX}/workspace_name/maps'),
+    ('rest_workspace_layers.get', False, {'workspace': 'workspace_name'},
+     f'http://enjoychallenge.tech/rest/{settings.REST_WORKSPACES_PREFIX}/workspace_name/layers'),
+    ('rest_about.get_version', True, {}, 'http://layman:8000/rest/about/version'),
+    ('rest_about.get_version', False, {}, 'http://enjoychallenge.tech/rest/about/version'),
+])
+def test__url_for(endpoint, internal, params, expected_url):
+    server_name = 'layman:8000'
+    proxy_server_name = 'enjoychallenge.tech'
+    with app.app_context():
+        # pylint: disable=protected-access
+        assert util._url_for(endpoint, server_name=server_name, proxy_server_name=proxy_server_name, internal=internal,
+                             **params) == expected_url