diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,3 +1,7 @@
+## 1.4.4.1
+
+* runFormPost has wrong behavior for empty forms [#950](https://github.com/yesodweb/yesod/issues/950)
+
 ## 1.4.4
 
 * Add a `Semigroup` instance
diff --git a/Yesod/Form/Functions.hs b/Yesod/Form/Functions.hs
--- a/Yesod/Form/Functions.hs
+++ b/Yesod/Form/Functions.hs
@@ -223,6 +223,7 @@
     ((res, xml), enctype) <- runFormGeneric (form token) m langs env
     let res' =
             case (res, env) of
+                (_, Nothing) -> FormMissing
                 (FormSuccess{}, Just (params, _))
                     | not (Map.lookup tokenKey params === reqToken req) ->
                         FormFailure [renderMessage m langs MsgCsrfWarning]
diff --git a/yesod-form.cabal b/yesod-form.cabal
--- a/yesod-form.cabal
+++ b/yesod-form.cabal
@@ -1,5 +1,5 @@
 name:            yesod-form
-version:         1.4.4
+version:         1.4.4.1
 license:         MIT
 license-file:    LICENSE
 author:          Michael Snoyman <michael@snoyman.com>