diff --git a/test/test_app.py b/test/test_app.py
index 1078b3a6e..84d2e8e54 100644
--- a/test/test_app.py
+++ b/test/test_app.py
@@ -6,7 +6,7 @@ class TestApp(tutils.DaemonTests):
         r = self.getpath("/")
         assert r.status_code == 200
         assert r.content
-        
+
     def test_docs(self):
         assert self.getpath("/docs/pathod").status_code == 200
         assert self.getpath("/docs/pathoc").status_code == 200
@@ -21,3 +21,17 @@ class TestApp(tutils.DaemonTests):
         assert self.getpath("/log/%s"%id).status_code == 200
         assert self.getpath("/log/9999999").status_code == 404
 
+    def test_preview(self):
+        r = self.getpath("/preview", params=dict(spec="200"))
+        assert r.status_code == 200
+        assert 'Response' in r.content
+
+        r = self.getpath("/preview", params=dict(spec="foo"))
+        assert r.status_code == 200
+        assert 'Error' in r.content
+
+        r = self.getpath("/preview", params=dict(spec="200:b@100m"))
+        assert r.status_code == 200
+        assert "too large" in r.content
+
+
diff --git a/test/tutils.py b/test/tutils.py
index 3c1b415ed..3b430825f 100644
--- a/test/tutils.py
+++ b/test/tutils.py
@@ -20,9 +20,11 @@ class DaemonTests:
     def setUp(self):
         self.d.clear_log()
 
-    def getpath(self, path):
+    def getpath(self, path, params=None):
         scheme = "https" if self.SSL else "http"
-        return requests.get("%s://localhost:%s/%s"%(scheme, self.d.port, path), verify=False)
+        return requests.get(
+            "%s://localhost:%s/%s"%(scheme, self.d.port, path), verify=False, params=params
+        )
 
     def get(self, spec):
         scheme = "https" if self.SSL else "http"