diff --git a/spago.yaml b/spago.yaml
index 057e339..95ebeed 100644
--- a/spago.yaml
+++ b/spago.yaml
@@ -10,6 +10,7 @@ package:
     - effect
     - either
     - exceptions
+    - foldable-traversable
     - foreign
     - fork
     - maybe
diff --git a/src/Data.Postgres.Query.Builder.purs b/src/Data.Postgres.Query.Builder.purs
index 8edd317..afd5e54 100644
--- a/src/Data.Postgres.Query.Builder.purs
+++ b/src/Data.Postgres.Query.Builder.purs
@@ -2,8 +2,9 @@ module Data.Postgres.Query.Builder where
 
 import Prelude
 
-import Control.Monad.State (StateT, modify, runStateT)
+import Control.Monad.State (StateT, get, modify, runStateT)
 import Data.Array as Array
+import Data.Foldable (any, elem)
 import Data.Set (Set)
 import Data.Set as Set
 import Data.Tuple.Nested (type (/\))
@@ -18,6 +19,11 @@ runBuilder = flip runStateT { params: [], refs: Set.empty }
 reference :: forall m. Monad m => String -> BuilderT m Unit
 reference k = void $ modify (\s@{ refs } -> s { refs = Set.insert k refs })
 
+isReferenced :: forall m. Monad m => Array String -> BuilderT m Boolean
+isReferenced ts = do
+  { refs } <- get
+  pure $ any (flip elem ts) refs
+
 param :: forall m a. Monad m => ToSQLValue a => a -> BuilderT m String
 param p =
   do