diff --git a/Language/Haskell/Syntax.hs b/Language/Haskell/Syntax.hs
--- a/Language/Haskell/Syntax.hs
+++ b/Language/Haskell/Syntax.hs
@@ -162,9 +162,9 @@
 data HsModule = HsModule SrcLoc Module (Maybe [HsExportSpec])
                          [HsImportDecl] [HsDecl]
 #ifdef __GLASGOW_HASKELL__
-  deriving (Show,Typeable,Data)
+  deriving (Eq,Show,Typeable,Data)
 #else
-  deriving (Show)
+  deriving (Eq,Show)
 #endif
 
 -- | Export specification.
diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,3 +1,9 @@
+## 1.0.4
+
+_Andreas Abel, 2022-02-07_
+
+  - Add `Eq` instance for `HsModule`.
+
 ## 1.0.3.2
 
 _Andreas Abel, 2022-02-07_
diff --git a/haskell-src.cabal b/haskell-src.cabal
--- a/haskell-src.cabal
+++ b/haskell-src.cabal
@@ -1,7 +1,7 @@
 cabal-version:  >=1.10
 name:           haskell-src
 -- don't forget to update the changelog.md!
-version:        1.0.3.2
+version:        1.0.4
 build-type:     Simple
 
 license:        BSD3