diff --git a/siphon/test/Doctest.hs b/siphon/test/Doctest.hs
index d41bded..34f8d73 100644
--- a/siphon/test/Doctest.hs
+++ b/siphon/test/Doctest.hs
@@ -2,6 +2,7 @@ import Test.DocTest
 
 main :: IO ()
 main = doctest
-  [ "src/Siphon.hs"
+  [ "-isrc"
+  , "src/Siphon.hs"
   ]