diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -34,5 +34,5 @@
 Get '[JSON] [String]
 ```
 
-See the documentation of `flatten` in `src/Servant/API/Flatten.hs`
-for more explanations and some examples.
+See the documentation of `flatten` in `Servant.Flatten`
+for more.
diff --git a/servant-flatten.cabal b/servant-flatten.cabal
--- a/servant-flatten.cabal
+++ b/servant-flatten.cabal
@@ -1,5 +1,5 @@
 name:                servant-flatten
-version:             0.1
+version:             0.2
 synopsis:            Utilities for flattening servant API types
 description:         Utilities for flattening servant API types
                      .
@@ -15,7 +15,7 @@
 build-type:          Simple
 extra-source-files:  ChangeLog.md, README.md
 cabal-version:       >=1.10
-tested-with:         GHC == 8.0.2, GHC == 8.2.2, GHC == 8.4.1
+tested-with:         GHC == 8.0.2, GHC == 8.2.2
 
 source-repository head
   type:     git
diff --git a/src/Servant/API/Flatten.hs b/src/Servant/API/Flatten.hs
--- a/src/Servant/API/Flatten.hs
+++ b/src/Servant/API/Flatten.hs
@@ -69,7 +69,7 @@
 flatten Proxy = Proxy
 
 -- | Flatten and transform the API type a little bit.
-type Flat api = Reassoc (Flatten (Reassoc (Flatten api)))
+type Flat api = Reassoc (Flatten api)
 -- looks like Flatten/Reassoc are missing some opportunities the first time,
 -- so we apply them twice for now...
 
@@ -87,11 +87,15 @@
   Redex a a first = Flatten first :> a
   Redex a b first = Flatten (first :> b)
 
--- | Reassociates '(:<|>)' to the right.
-type family Reassoc api where
-  Reassoc ((a :<|> b) :<|> c) = Reassoc a :<|> Reassoc (b :<|> c)
-  Reassoc (a :<|> b) = a :<|> Reassoc b
-  Reassoc a = a
+-- | Reassociates ':<|>' to the right.
+type Reassoc api = ReassocBranch api '[]
+
+-- | Helper type family that "enumerates" the different endpoints left
+--   to right.
+type family ReassocBranch (currentAPI :: *) (otherEndpoints :: [*]) where
+  ReassocBranch (a :<|> b)        rest = ReassocBranch a (b ': rest)
+  ReassocBranch a                  '[] = a
+  ReassocBranch a          (b ': rest) = a :<|> ReassocBranch b rest
 
 -- * Utilities that we can define on a flat representation