diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Revision history for blucontrol
 
+## 0.5.1.1 *21 Jun 2021*
+
+* Allow building against new versions of X11.
+
 ## 0.5.1.0 *19 Jun 2021*
 
 * `RecolorXT` now uses `RecolorXValue`, which is just a newtype of the old `RGB Float`.
diff --git a/blucontrol.cabal b/blucontrol.cabal
--- a/blucontrol.cabal
+++ b/blucontrol.cabal
@@ -1,5 +1,5 @@
 name:                blucontrol
-version:             0.5.1.0
+version:             0.5.1.1
 synopsis:            Configurable blue light filter
 description:         This application is a blue light filter, with the main focus on
                      configurability.
@@ -64,7 +64,7 @@
                      , transformers      >= 0.5.6.2 && < 0.5.7
                      , transformers-base >= 0.4.5.2 && < 0.5
                      , unix              >= 2.7.2.2 && < 2.8
-                     , X11               >= 1.9     && < 1.10
+                     , X11               >= 1.9     && < 2
   hs-source-dirs:      src
   includes:            XrandrGamma.h
   extra-libraries:     X11, Xrandr