diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,9 @@
 # Revision history for greskell-websocket
 
+## 0.1.2.3  -- 2020-05-30
+
+* Support `aeson-1.5.0.0`.
+
 ## 0.1.2.2  -- 2020-05-04
 
 * Confirm test with `base64-bytestring-1.1.0.0`.
diff --git a/greskell-websocket.cabal b/greskell-websocket.cabal
--- a/greskell-websocket.cabal
+++ b/greskell-websocket.cabal
@@ -1,5 +1,5 @@
 name:                   greskell-websocket
-version:                0.1.2.2
+version:                0.1.2.3
 author:                 Toshio Ito <debug.ito@gmail.com>
 maintainer:             Toshio Ito <debug.ito@gmail.com>
 license:                BSD3
@@ -48,7 +48,7 @@
                         bytestring >=0.10.8.1 && <0.11,
                         base64-bytestring >=1.0.0.1 && <1.2,
                         text >=1.2.2.2 && <1.3,
-                        aeson >=1.1.2.0 && <1.5,
+                        aeson >=1.1.2.0 && <1.6,
                         unordered-containers >=0.2.8 && <0.3,
                         uuid >=1.3.13 && <1.4,
                         async >=2.1.1.1 && <2.3,