diff --git a/moto/core/responses.py b/moto/core/responses.py
index 6f8b365fb..7e896e961 100644
--- a/moto/core/responses.py
+++ b/moto/core/responses.py
@@ -55,17 +55,26 @@ def metadata_response(request, full_url, headers):
 
     http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/AESDG-chapter-instancedata.html
     """
-
     parsed_url = urlparse(full_url)
     tomorrow = datetime.datetime.now() + datetime.timedelta(days=1)
+    credentials = dict(
+        AccessKeyId="test-key",
+        SecretAccessKey="test-secret-key",
+        Token="test-session-token",
+        Expiration=tomorrow.strftime("%Y-%m-%dT%H:%M:%SZ")
+    )
+
     path = parsed_url.path.lstrip("/latest/meta-data/")
-    if path == 'iam/security-credentials/':
+    if path == '':
+        result = 'iam'
+    elif path == 'iam':
+        result = json.dumps({
+            'security-credentials': {
+                'default-role': credentials
+            }
+        })
+    elif path == 'iam/security-credentials/':
         result = 'default-role'
     elif path == 'iam/security-credentials/default-role':
-        result = json.dumps(dict(
-            AccessKeyId="test-key",
-            SecretAccessKey="test-secret-key",
-            Token="test-session-token",
-            Expiration=tomorrow.strftime("%Y-%m-%dT%H:%M:%SZ")
-        ))
+        result = json.dumps(credentials)
     return 200, headers, result
diff --git a/tests/test_ec2/test_instances.py b/tests/test_ec2/test_instances.py
index 47e8b4b16..11c2cc00e 100644
--- a/tests/test_ec2/test_instances.py
+++ b/tests/test_ec2/test_instances.py
@@ -9,7 +9,7 @@ from moto import mock_ec2
 
 ################ Test Readme ###############
 def add_servers(ami_id, count):
-    conn = boto.connect_ec2('the_key', 'the_secret')
+    conn = boto.connect_ec2()
     for index in range(count):
         conn.run_instances(ami_id)
 
@@ -18,7 +18,7 @@ def add_servers(ami_id, count):
 def test_add_servers():
     add_servers('ami-1234abcd', 2)
 
-    conn = boto.connect_ec2('the_key', 'the_secret')
+    conn = boto.connect_ec2()
     reservations = conn.get_all_instances()
     assert len(reservations) == 2
     instance1 = reservations[0].instances[0]