diff --git a/trove/common/apischema.py b/trove/common/apischema.py
index fed3bf231e..e714a6526d 100644
--- a/trove/common/apischema.py
+++ b/trove/common/apischema.py
@@ -50,7 +50,7 @@ configuration_positive_integer = {
     "type": "string",
     "maxLength": 40,
     "minLength": 1,
-    "pattern": "^[0-9]+$"
+    "pattern": "^0*[1-9]+[0-9]*$"
 }
 
 configuration_non_empty_string = {
@@ -72,7 +72,7 @@ volume_size = {
     "oneOf": [
         {
             "type": "integer",
-            "minimum": 0
+            "minimum": 1
         },
         configuration_positive_integer]
 }
diff --git a/trove/tests/api/mgmt/malformed_json.py b/trove/tests/api/mgmt/malformed_json.py
index 088ec8058d..bc7e28c6b7 100644
--- a/trove/tests/api/mgmt/malformed_json.py
+++ b/trove/tests/api/mgmt/malformed_json.py
@@ -168,7 +168,7 @@ class MalformedJson(object):
                  "resize['volume']['size'] %s is not valid under "
                  "any of the given schemas" % data,
                  "%s is not of type 'integer'" % data,
-                 "%s does not match '^[0-9]+$'" % data])
+                 "%s does not match '^0*[1-9]+[0-9]*$'" % data])
 
     @test
     def test_bad_change_user_password(self):
diff --git a/trove/tests/unittests/instance/test_instance_controller.py b/trove/tests/unittests/instance/test_instance_controller.py
index 00aabe2b71..40a7dbfc66 100644
--- a/trove/tests/unittests/instance/test_instance_controller.py
+++ b/trove/tests/unittests/instance/test_instance_controller.py
@@ -190,6 +190,12 @@ class TestInstanceController(trove_testtools.TestCase):
         validator = jsonschema.Draft4Validator(schema)
         self.assertTrue(validator.is_valid(body))
 
+    def test_validate_resize_volume_string_start_with_zero(self):
+        body = {"resize": {"volume": {"size": "0040"}}}
+        schema = self.controller.get_schema('action', body)
+        validator = jsonschema.Draft4Validator(schema)
+        self.assertTrue(validator.is_valid(body))
+
     def test_validate_resize_volume_string_invalid_number(self):
         body = {"resize": {"volume": {"size": '-44.0'}}}
         schema = self.controller.get_schema('action', body)
@@ -197,7 +203,7 @@ class TestInstanceController(trove_testtools.TestCase):
         self.assertFalse(validator.is_valid(body))
         errors = sorted(validator.iter_errors(body), key=lambda e: e.path)
         self.assertThat(errors[0].context[1].message,
-                        Equals("'-44.0' does not match '^[0-9]+$'"))
+                        Equals("'-44.0' does not match '^0*[1-9]+[0-9]*$'"))
         self.assertThat(errors[0].path.pop(), Equals('size'))
 
     def test_validate_resize_volume_invalid_characters(self):
@@ -209,7 +215,27 @@ class TestInstanceController(trove_testtools.TestCase):
         self.assertThat(errors[0].context[0].message,
                         Equals("'x' is not of type 'integer'"))
         self.assertThat(errors[0].context[1].message,
-                        Equals("'x' does not match '^[0-9]+$'"))
+                        Equals("'x' does not match '^0*[1-9]+[0-9]*$'"))
+        self.assertThat(errors[0].path.pop(), Equals('size'))
+
+    def test_validate_resize_volume_zero_number(self):
+        body = {"resize": {"volume": {"size": 0}}}
+        schema = self.controller.get_schema('action', body)
+        validator = jsonschema.Draft4Validator(schema)
+        self.assertFalse(validator.is_valid(body))
+        errors = sorted(validator.iter_errors(body), key=lambda e: e.path)
+        self.assertThat(errors[0].context[0].message,
+                        Equals("0 is less than the minimum of 1"))
+        self.assertThat(errors[0].path.pop(), Equals('size'))
+
+    def test_validate_resize_volume_string_zero_number(self):
+        body = {"resize": {"volume": {"size": '0'}}}
+        schema = self.controller.get_schema('action', body)
+        validator = jsonschema.Draft4Validator(schema)
+        self.assertFalse(validator.is_valid(body))
+        errors = sorted(validator.iter_errors(body), key=lambda e: e.path)
+        self.assertThat(errors[0].context[1].message,
+                        Equals("'0' does not match '^0*[1-9]+[0-9]*$'"))
         self.assertThat(errors[0].path.pop(), Equals('size'))
 
     def test_validate_resize_instance(self):