diff --git a/UPGRADING.md b/UPGRADING.md
index 67143a6..9ac0088 100644
--- a/UPGRADING.md
+++ b/UPGRADING.md
@@ -28,7 +28,10 @@
 Only discovery documents listed in [this public directory](https://www.googleapis.com/discovery/v1/apis/)
 are included in the library. Users of private APIs should set the
 `static_discovery` argument of `discovery.build()` to `False` to continue to
-retrieve the service definition from the internet.
+retrieve the service definition from the internet. As of version 2.1.0,
+for backwards compatability with version 1.x, if `static_discovery` is not
+specified, the default value for `static_discovery` will be `True` when
+the `discoveryServiceUrl` argument of `discovery.build()` is provided.
 
 If you experience issues or have questions, please file an [issue](https://github.com/googleapis/google-api-python-client/issues).
 
diff --git a/googleapiclient/discovery.py b/googleapiclient/discovery.py
index a81ceca..4281ebb 100644
--- a/googleapiclient/discovery.py
+++ b/googleapiclient/discovery.py
@@ -182,7 +182,7 @@
     serviceName,
     version,
     http=None,
-    discoveryServiceUrl=DISCOVERY_URI,
+    discoveryServiceUrl=None,
     developerKey=None,
     model=None,
     requestBuilder=HttpRequest,
@@ -193,7 +193,7 @@
     adc_cert_path=None,
     adc_key_path=None,
     num_retries=1,
-    static_discovery=True,
+    static_discovery=None,
 ):
     """Construct a Resource for interacting with an API.
 
@@ -248,7 +248,10 @@
     num_retries: Integer, number of times to retry discovery with
       randomized exponential backoff in case of intermittent/connection issues.
     static_discovery: Boolean, whether or not to use the static discovery docs
-      included in the library.
+      included in the library. The default value for `static_discovery` depends
+      on the value of `discoveryServiceUrl`. `static_discovery` will default to
+      `True` when `discoveryServiceUrl` is also not provided, otherwise it will
+      default to `False`.
 
   Returns:
     A Resource object with methods for interacting with the service.
@@ -259,6 +262,21 @@
   """
     params = {"api": serviceName, "apiVersion": version}
 
+    # The default value for `static_discovery` depends on the value of
+    # `discoveryServiceUrl`. `static_discovery` will default to `True` when
+    # `discoveryServiceUrl` is also not provided, otherwise it will default to
+    # `False`. This is added for backwards compatability with
+    # google-api-python-client 1.x which does not support the `static_discovery`
+    # parameter.
+    if static_discovery is None:
+        if discoveryServiceUrl is None:
+            static_discovery = True
+        else:
+            static_discovery = False
+
+    if discoveryServiceUrl is None:
+        discoveryServiceUrl = DISCOVERY_URI
+
     if http is None:
         discovery_http = build_http()
     else:
diff --git a/tests/test_discovery.py b/tests/test_discovery.py
index fbb6475..43ab2c7 100644
--- a/tests/test_discovery.py
+++ b/tests/test_discovery.py
@@ -592,7 +592,7 @@
 
     def test_resource_close(self):
         discovery = read_datafile("plus.json")
-        
+
         with mock.patch("httplib2.Http", autospec=True) as httplib2_http:
             http = httplib2_http()
             plus = build_from_document(
@@ -927,8 +927,7 @@
                 "v1",
                 http=http,
                 developerKey=None,
-                discoveryServiceUrl="http://example.com",
-                static_discovery=False,
+                discoveryServiceUrl="http://example.com"
             )
             self.fail("Should have raised an exception.")
         except HttpError as e:
@@ -946,8 +945,7 @@
                 "v1",
                 http=http,
                 developerKey=None,
-                discoveryServiceUrl="http://example.com",
-                static_discovery=False,
+                discoveryServiceUrl="http://example.com"
             )
             self.fail("Should have raised an exception.")
         except HttpError as e: