diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Change log
 
+## 0.4.0.4
+
+* Relax upper bound on `fast-logger`: 2.11 -> 2.12
+
 ## 0.4.0.3
 
 * Relax upper bound on `fast-logger`: 3.2.0 -> 3.3.0
diff --git a/monad-logger-aeson.cabal b/monad-logger-aeson.cabal
--- a/monad-logger-aeson.cabal
+++ b/monad-logger-aeson.cabal
@@ -5,7 +5,7 @@
 -- see: https://github.com/sol/hpack
 
 name:           monad-logger-aeson
-version:        0.4.0.3
+version:        0.4.0.4
 synopsis:       JSON logging using monad-logger interface
 description:    @monad-logger-aeson@ provides structured JSON logging using @monad-logger@'s
                 interface.
@@ -150,7 +150,7 @@
     , base >=4.11.1.0 && <5
     , bytestring >=0.10.8.2 && <0.12.0.0
     , directory >=1.3.1.5 && <1.4.0.0
-    , hspec >=2.7.9 && <2.11
+    , hspec >=2.7.9 && <2.12
     , monad-logger >=0.3.30 && <0.4.0
     , monad-logger-aeson
     , time >=1.8.0.2 && <1.14
diff --git a/package.yaml b/package.yaml
--- a/package.yaml
+++ b/package.yaml
@@ -1,5 +1,5 @@
 name: monad-logger-aeson
-version: '0.4.0.3'
+version: '0.4.0.4'
 github: "jship/monad-logger-aeson"
 license: MIT
 license-file: LICENSE.md
@@ -53,7 +53,7 @@
     - base >=4.11.1.0 && <5
     - bytestring >=0.10.8.2 && <0.12.0.0
     - directory >=1.3.1.5 && <1.4.0.0
-    - hspec >=2.7.9 && <2.11
+    - hspec >=2.7.9 && <2.12
     - monad-logger >=0.3.30 && <0.4.0
     - monad-logger-aeson
     - time >=1.8.0.2 && <1.14