diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,9 @@
-## [_Unreleased_](https://github.com/thoughtbot/yesod-auth-oauth2/compare/v0.7.1.2...main)
+## [_Unreleased_](https://github.com/thoughtbot/yesod-auth-oauth2/compare/v0.7.1.3...main)
+
+## [v0.7.1.3](https://github.com/thoughtbot/yesod-auth-oauth2/compare/v0.7.1.2...v0.7.1.3)
+
+- Add support (with caveats) for relative approots
+  [@cptrodolfox](https://github.com/freckle/yesod-auth-oauth2/pull/178)
 
 ## [v0.7.1.2](https://github.com/thoughtbot/yesod-auth-oauth2/compare/v0.7.1.1...v0.7.1.2)
 
diff --git a/src/Yesod/Auth/OAuth2/Dispatch.hs b/src/Yesod/Auth/OAuth2/Dispatch.hs
--- a/src/Yesod/Auth/OAuth2/Dispatch.hs
+++ b/src/Yesod/Auth/OAuth2/Dispatch.hs
@@ -105,14 +105,17 @@
   -> Text
   -> m OAuth2
 withCallbackAndState name oauth2 csrf = do
-  uri <- ($ PluginR name ["callback"]) <$> getParentUrlRender
-  callback <- maybe (throwError $ InvalidCallbackUri uri) pure $ fromText uri
+  callback <- maybe defaultCallback pure $ oauth2RedirectUri oauth2
   pure
     oauth2
       { oauth2RedirectUri = Just callback
       , oauth2AuthorizeEndpoint =
           oauth2AuthorizeEndpoint oauth2 `withQuery` [("state", encodeUtf8 csrf)]
       }
+ where
+  defaultCallback = do
+    uri <- ($ PluginR name ["callback"]) <$> getParentUrlRender
+    maybe (throwError $ InvalidCallbackUri uri) pure $ fromText uri
 
 getParentUrlRender :: MonadHandler m => m (Route (SubHandlerSite m) -> Text)
 getParentUrlRender = (.) <$> getUrlRender <*> getRouteToParent
diff --git a/yesod-auth-oauth2.cabal b/yesod-auth-oauth2.cabal
--- a/yesod-auth-oauth2.cabal
+++ b/yesod-auth-oauth2.cabal
@@ -1,6 +1,6 @@
 cabal-version:   1.18
 name:            yesod-auth-oauth2
-version:         0.7.1.2
+version:         0.7.1.3
 license:         MIT
 license-file:    LICENSE
 maintainer:      engineering@freckle.com