diff --git a/dbt/clients/jinja.py b/dbt/clients/jinja.py
index 9f85c553116..40cf1ae5950 100644
--- a/dbt/clients/jinja.py
+++ b/dbt/clients/jinja.py
@@ -246,7 +246,7 @@ def __call__(self, *args, **kwargs):
 
 def get_environment(node=None, capture_macros=False):
     args = {
-        'extensions': []
+        'extensions': ['jinja2.ext.do']
     }
 
     if capture_macros:
diff --git a/test/unit/test_jinja.py b/test/unit/test_jinja.py
new file mode 100644
index 00000000000..21abd573b5b
--- /dev/null
+++ b/test/unit/test_jinja.py
@@ -0,0 +1,11 @@
+import unittest
+
+from dbt.clients.jinja import get_template
+
+class TestJinja(unittest.TestCase):
+    def test_do(self):
+        s = '{% set my_dict = {} %}\n{% do my_dict.update(a=1) %}'
+
+        template = get_template(s, {})
+        mod = template.make_module()
+        self.assertEqual(mod.my_dict, {'a': 1})