diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,9 @@
 # ChangeLog for yesod-core
 
+## 1.6.20.2
+
+* Fix compatibility with template-haskell 2.17 [#1729](https://github.com/yesodweb/yesod/pull/1729)
+
 ## 1.6.20.1
 
 * Throw an error in `breadcrumbs` if the trail of breadcrumbs is circular. [#1727](https://github.com/yesodweb/yesod/issues/1727)
diff --git a/src/Yesod/Core/Internal/TH.hs b/src/Yesod/Core/Internal/TH.hs
--- a/src/Yesod/Core/Internal/TH.hs
+++ b/src/Yesod/Core/Internal/TH.hs
@@ -107,9 +107,9 @@
 -- | Get the Handler and Widget type synonyms for the given site.
 masterTypeSyns :: [Name] -> Type -> [Dec] -- FIXME remove from here, put into the scaffolding itself?
 masterTypeSyns vs site =
-    [ TySynD (mkName "Handler") (fmap PlainTV vs)
+    [ TySynD (mkName "Handler") (fmap plainTV vs)
       $ ConT ''HandlerFor `AppT` site
-    , TySynD (mkName "Widget")  (fmap PlainTV vs)
+    , TySynD (mkName "Widget")  (fmap plainTV vs)
       $ ConT ''WidgetFor `AppT` site `AppT` ConT ''()
     ]
 
diff --git a/yesod-core.cabal b/yesod-core.cabal
--- a/yesod-core.cabal
+++ b/yesod-core.cabal
@@ -1,5 +1,5 @@
 name:            yesod-core
-version:         1.6.20.1
+version:         1.6.20.2
 license:         MIT
 license-file:    LICENSE
 author:          Michael Snoyman <michael@snoyman.com>