diff --git a/src/PostgREST/DbStructure.hs b/src/PostgREST/DbStructure.hs
index 5e5819418..98a2c43a0 100644
--- a/src/PostgREST/DbStructure.hs
+++ b/src/PostgREST/DbStructure.hs
@@ -100,8 +100,8 @@ queryDbStructure schemas extraSearchPath prepared = do
     , dbProcs = procs
     }
   where
-    relsToMap = map sort . M.fromListWith (++) . map ((\(x,y) -> (x, [y])) . addKey)
-    addKey rel = (relTable rel, rel)
+    relsToMap = map sort . M.fromListWith (++) . map ((\(x, fSch, y) -> ((x, fSch), [y])) . addKey)
+    addKey rel = (relTable rel, qiSchema $ relForeignTable rel, rel)
 
 -- | Remove db objects that belong to an internal schema(not exposed through the API) from the DbStructure.
 removeInternal :: [Schema] -> DbStructure -> DbStructure
@@ -109,7 +109,7 @@ removeInternal schemas dbStruct =
   DbStructure {
       dbTables        = M.filterWithKey (\(QualifiedIdentifier sch _) _ -> sch `elem` schemas) $ dbTables dbStruct
     , dbRelationships = filter (\r -> qiSchema (relForeignTable r) `elem` schemas && not (hasInternalJunction r)) <$>
-                        M.filterWithKey (\(QualifiedIdentifier sch _) _ -> sch `elem` schemas ) (dbRelationships dbStruct)
+                        M.filterWithKey (\(QualifiedIdentifier sch _, _) _ -> sch `elem` schemas ) (dbRelationships dbStruct)
     , dbProcs         = dbProcs dbStruct -- procs are only obtained from the exposed schemas, no need to filter them.
     }
   where
diff --git a/src/PostgREST/DbStructure/Relationship.hs b/src/PostgREST/DbStructure/Relationship.hs
index 391cba85f..4a48b39be 100644
--- a/src/PostgREST/DbStructure/Relationship.hs
+++ b/src/PostgREST/DbStructure/Relationship.hs
@@ -13,7 +13,7 @@ import qualified Data.Aeson          as JSON
 import qualified Data.HashMap.Strict as M
 
 import PostgREST.DbStructure.Identifiers (FieldName,
-                                          QualifiedIdentifier)
+                                          QualifiedIdentifier, Schema)
 
 import Protolude
 
@@ -53,4 +53,5 @@ data Junction = Junction
 isSelfReference :: Relationship -> Bool
 isSelfReference r = relTable r == relForeignTable r
 
-type RelationshipsMap = M.HashMap QualifiedIdentifier [Relationship]
+-- | Key based on the source table and the foreign table schema
+type RelationshipsMap = M.HashMap (QualifiedIdentifier, Schema)  [Relationship]
diff --git a/src/PostgREST/OpenAPI.hs b/src/PostgREST/OpenAPI.hs
index 7a04fb95d..0a446adff 100644
--- a/src/PostgREST/OpenAPI.hs
+++ b/src/PostgREST/OpenAPI.hs
@@ -100,7 +100,7 @@ makeProperty tbl rels col = (colName col, Inline s)
         rel = find (\case
           Relationship{relCardinality=(M2O _ relColumns)} -> [colName col] == (fst <$> relColumns)
           _                                               -> False
-          ) $ fromMaybe mempty $ M.lookup (QualifiedIdentifier (tableSchema tbl) (tableName tbl)) rels
+          ) $ fromMaybe mempty $ M.lookup (QualifiedIdentifier (tableSchema tbl) (tableName tbl), tableSchema tbl) rels
         fCol = (headMay . (\r -> snd <$> relColumns (relCardinality r)) =<< rel)
         fTbl = qiName . relForeignTable <$> rel
         fTblCol = (,) <$> fTbl <*> fCol
diff --git a/src/PostgREST/Request/DbRequestBuilder.hs b/src/PostgREST/Request/DbRequestBuilder.hs
index 913735751..b65e09ddc 100644
--- a/src/PostgREST/Request/DbRequestBuilder.hs
+++ b/src/PostgREST/Request/DbRequestBuilder.hs
@@ -157,47 +157,54 @@ findRel schema allRels origin target hint =
     rs -> Left $ AmbiguousRelBetween origin target rs
   where
     matchFKSingleCol hint_ card = case card of
-      O2M _ cols -> length cols == 1 && hint_ == head (fst <$> cols)
-      M2O _ cols -> length cols == 1 && hint_ == head (fst <$> cols)
-      _          -> False
+      O2M _ [(col, _)] -> hint_ == col
+      M2O _ [(col, _)] -> hint_ == col
+      _                -> False
     matchFKRefSingleCol hint_ card = case card of
-      O2M _ cols -> length cols == 1 && hint_ == head (snd <$> cols)
-      M2O _ cols -> length cols == 1 && hint_ == head (snd <$> cols)
-      _          -> False
+      O2M _ [(_, fCol)] -> hint_ == fCol
+      M2O _ [(_, fCol)] -> hint_ == fCol
+      _                 -> False
     matchConstraint tar card = case card of
-      O2M cons _ -> tar == Just cons
-      M2O cons _ -> tar == Just cons
+      O2M cons _ -> tar == cons
+      M2O cons _ -> tar == cons
       _          -> False
     matchJunction hint_ card = case card of
-      M2M Junction{junTable} -> hint_ == Just (qiName junTable)
+      M2M Junction{junTable} -> hint_ == qiName junTable
       _                      -> False
     rel = filter (
       \Relationship{..} ->
-        -- foreign relationship need to be on the exposed schema
-        schema == qiSchema relForeignTable &&
-        (
-          -- /projects?select=clients(*)
-          target == qiName relForeignTable  -- clients
-          ||
-          -- /projects?select=projects_client_id_fkey(*)
-          matchConstraint (Just target) relCardinality -- projects_client_id_fkey
-          ||
-          -- /projects?select=client_id(*)
-          matchFKSingleCol (Just target) relCardinality -- client_id
-        ) && (
-          isNothing hint || -- hint is optional
+        case hint of
+          Nothing ->
+              -- /projects?select=clients(*)
+              target == qiName relForeignTable  -- clients
+              ||
+              -- /projects?select=projects_client_id_fkey(*)
+              matchConstraint target relCardinality -- projects_client_id_fkey
+              ||
+              -- /projects?select=client_id(*)
+              matchFKSingleCol target relCardinality -- client_id
+          Just hnt ->
+            (
+              -- /projects?select=clients(*)
+              target == qiName relForeignTable  -- clients
+              ||
+              -- /projects?select=projects_client_id_fkey(*)
+              matchConstraint target relCardinality -- projects_client_id_fkey
+              ||
+              -- /projects?select=client_id(*)
+              matchFKSingleCol target relCardinality -- client_id
+            ) && (
+              -- /projects?select=clients!projects_client_id_fkey(*)
+              matchConstraint hnt relCardinality || -- projects_client_id_fkey
 
-          -- /projects?select=clients!projects_client_id_fkey(*)
-          matchConstraint hint relCardinality || -- projects_client_id_fkey
+              -- /projects?select=clients!client_id(*) or /projects?select=clients!id(*)
+              matchFKSingleCol hnt relCardinality    || -- client_id
+              matchFKRefSingleCol hnt relCardinality || -- id
 
-          -- /projects?select=clients!client_id(*) or /projects?select=clients!id(*)
-          matchFKSingleCol hint relCardinality    || -- client_id
-          matchFKRefSingleCol hint relCardinality || -- id
-
-          -- /users?select=tasks!users_tasks(*) many-to-many between users and tasks
-          matchJunction hint relCardinality -- users_tasks
-        )
-      ) $ fromMaybe mempty $ M.lookup (QualifiedIdentifier schema origin) allRels
+              -- /users?select=tasks!users_tasks(*) many-to-many between users and tasks
+              matchJunction hnt relCardinality -- users_tasks
+            )
+      ) $ fromMaybe mempty $ M.lookup (QualifiedIdentifier schema origin, schema) allRels
 
 -- previousAlias is only used for the case of self joins
 addJoinConditions :: Maybe Alias -> ReadRequest -> Either ApiRequestError ReadRequest
diff --git a/test/spec/Feature/OpenApi/RootSpec.hs b/test/spec/Feature/OpenApi/RootSpec.hs
index e5b8d3f96..420a3e6a4 100644
--- a/test/spec/Feature/OpenApi/RootSpec.hs
+++ b/test/spec/Feature/OpenApi/RootSpec.hs
@@ -26,7 +26,7 @@ spec =
     it "accepts application/json" $
       request methodGet "/"
         [("Accept", "application/json")] "" `shouldRespondWith`
-        [json| {
-          "qiSchema":"test","qiName":"bars"
-          } |]
+        [json|
+            [{"qiSchema":"test","qiName":"authors_w_entities"},"test"]
+          |]
         { matchHeaders = [matchContentTypeJson] }