diff --git a/ckanext/datastore/db.py b/ckanext/datastore/db.py
index 81f3649916f..04c606cda32 100644
--- a/ckanext/datastore/db.py
+++ b/ckanext/datastore/db.py
@@ -1446,12 +1446,16 @@ def create_trigger_function(name, definition, or_replace):
 
 def drop_function(name, if_exists):
     sql = u'''
-        DROP FUNCTION {if_exists} {name};
+        DROP FUNCTION {if_exists} {name}();
         '''.format(
         if_exists=u'IF EXISTS' if if_exists else u'',
         name=datastore_helpers.identifier(name))
 
-    _write_engine_execute(sql)
+    try:
+        _write_engine_execute(sql)
+    except ProgrammingError as pe:
+        message = pe.args[0].split('\n')[0].decode('utf8')
+        raise ValidationError({u'name': [message.split(u') ', 1)[-1]]})
 
 
 def _write_engine_execute(sql):
diff --git a/ckanext/datastore/logic/action.py b/ckanext/datastore/logic/action.py
index c88b6e8dfcd..1120f2d627c 100644
--- a/ckanext/datastore/logic/action.py
+++ b/ckanext/datastore/logic/action.py
@@ -605,4 +605,4 @@ def datastore_function_delete(context, data_dict):
     '''
     p.toolkit.check_access('datastore_function_delete', context, data_dict)
 
-    db.drop_function(data_dict['name'])
+    db.drop_function(data_dict['name'], data_dict['if_exists'])
diff --git a/ckanext/datastore/logic/schema.py b/ckanext/datastore/logic/schema.py
index 1616f52d461..4931c7ae41c 100644
--- a/ckanext/datastore/logic/schema.py
+++ b/ckanext/datastore/logic/schema.py
@@ -179,4 +179,5 @@ def datastore_function_create_schema():
 def datastore_function_delete_schema():
     return {
         'name': [unicode_only, not_empty],
+        'if_exists': [default(False), boolean_validator],
     }
diff --git a/ckanext/datastore/tests/test_delete.py b/ckanext/datastore/tests/test_delete.py
index 745a5c68d84..67b46130406 100644
--- a/ckanext/datastore/tests/test_delete.py
+++ b/ckanext/datastore/tests/test_delete.py
@@ -1,5 +1,6 @@
 import json
 import nose
+from nose.tools import assert_equal
 
 import pylons
 import sqlalchemy
@@ -9,9 +10,11 @@
 import ckan.lib.create_test_data as ctd
 import ckan.model as model
 import ckan.tests.legacy as tests
+from ckan.plugins.toolkit import ValidationError
 
 import ckanext.datastore.db as db
-from ckanext.datastore.tests.helpers import rebuild_all_dbs, set_url_type
+from ckanext.datastore.tests.helpers import (
+    rebuild_all_dbs, set_url_type, DatastoreFunctionalTestBase)
 
 
 class TestDatastoreDelete(tests.WsgiAppCase):
@@ -234,3 +237,33 @@ def test_delete_with_blank_filters(self):
         assert(len(results['result']['records']) == 0)
 
         self._delete()
+
+
+class TestDatastoreFunctionDelete(DatastoreFunctionalTestBase):
+    def test_create_delete(self):
+        helpers.call_action(
+            u'datastore_function_create',
+            name=u'test_nop',
+            rettype=u'trigger',
+            definition=u'BEGIN RETURN NEW; END;')
+        helpers.call_action(
+            u'datastore_function_delete',
+            name=u'test_nop')
+
+    def test_delete_nonexistant(self):
+        try:
+            helpers.call_action(
+                u'datastore_function_delete',
+                name=u'test_not_there')
+        except ValidationError as ve:
+            assert_equal(
+                ve.error_dict,
+                {u'name': [u'function test_not_there() does not exist']})
+        else:
+            assert 0, u'no validation error'
+
+    def test_delete_if_exitst(self):
+        helpers.call_action(
+            u'datastore_function_delete',
+            name=u'test_not_there_either',
+            if_exists=True)