diff --git a/obspy/clients/fdsn/client.py b/obspy/clients/fdsn/client.py
index 667dc8d830a..b2fe87a7bd4 100644
--- a/obspy/clients/fdsn/client.py
+++ b/obspy/clients/fdsn/client.py
@@ -288,6 +288,7 @@ def set_credentials(self, user, password):
         :type password: str
         :param password: Password for given user name.
         """
+        self.user = user
         self._set_opener(user, password)
 
     def set_eida_token(self, token):
diff --git a/obspy/clients/fdsn/tests/test_client.py b/obspy/clients/fdsn/tests/test_client.py
index 84529d2f9ab..b3a17355386 100644
--- a/obspy/clients/fdsn/tests/test_client.py
+++ b/obspy/clients/fdsn/tests/test_client.py
@@ -282,6 +282,27 @@ def test_url_building_with_auth(self):
                     "queryauth?net=BW")
         self.assertEqual(got, expected)
 
+    def test_set_credentials(self):
+        """
+        Test for issue #2146
+
+        When setting credentials not during `__init__` but using
+        `set_credentials`, waveform queries should still properly go to
+        "queryauth" endpoint.
+        """
+        client = Client(base_url="IRIS", user_agent=USER_AGENT)
+        user = "nobody@iris.edu"
+        password = "anonymous"
+        client.set_credentials(user=user, password=password)
+        got = client._build_url("dataselect", "query", {'net': "BW"})
+        expected = ("http://service.iris.edu/fdsnws/dataselect/1/"
+                    "queryauth?net=BW")
+        self.assertEqual(got, expected)
+        # more basic test: check that set_credentials has set Client.user
+        # (which is tested when checking which endpoint to use, query or
+        # queryauth)
+        self.assertEqual(client.user, user)
+
     def test_service_discovery_iris(self):
         """
         Tests the automatic discovery of services with the IRIS endpoint. The