diff --git a/dec.cabal b/dec.cabal
new file mode 100644
index 0000000..c90fbfb
--- /dev/null
+++ b/dec.cabal
@@ -0,0 +1,56 @@
+cabal-version:      >=1.10
+name:               dec
+version:            0.0.4
+x-revision: 1
+synopsis:           Decidable propositions.
+category:           Data, Dependent Types
+description:
+  This package provides a @Dec@ type.
+  .
+  @
+  type Neg a = a -> Void
+  .
+  data Dec a
+  \    = Yes a
+  \    | No (Neg a)
+  @
+
+homepage:           https://github.com/phadej/vec
+bug-reports:        https://github.com/phadej/vec/issues
+license:            BSD3
+license-file:       LICENSE
+author:             Oleg Grenrus <oleg.grenrus@iki.fi>
+maintainer:         Oleg.Grenrus <oleg.grenrus@iki.fi>
+copyright:          (c) 2019-2021 Oleg Grenrus
+build-type:         Simple
+extra-source-files: ChangeLog.md
+tested-with:
+  GHC ==7.8.4
+   || ==7.10.3
+   || ==8.0.2
+   || ==8.2.2
+   || ==8.4.4
+   || ==8.6.5
+   || ==8.8.4
+   || ==8.10.3
+   || ==9.0.1
+
+source-repository head
+  type:     git
+  location: https://github.com/phadej/vec.git
+  subdir:   dec
+
+library
+  default-language: Haskell2010
+  hs-source-dirs:   src
+  ghc-options:      -Wall -fprint-explicit-kinds
+  exposed-modules:  Data.Type.Dec
+  build-depends:    base >=4.7 && <4.17
+
+  if !impl(ghc >=7.10)
+    build-depends: void >=0.7.3 && <0.8
+
+  if impl(ghc >= 9.0)
+    -- these flags may abort compilation with GHC-8.10
+    -- https://gitlab.haskell.org/ghc/ghc/-/merge_requests/3295
+    ghc-options: -Winferred-safe-imports -Wmissing-safe-haskell-mode
diff --git a/ghc-dec.changes b/ghc-dec.changes
index 598e564..c281a87 100644
--- a/ghc-dec.changes
+++ b/ghc-dec.changes
@@ -1,3 +1,9 @@
+-------------------------------------------------------------------
+Fri Feb  4 12:15:11 UTC 2022 - psimons@suse.com
+
+- Update dec to version 0.0.4 revision 1.
+  Upstream has revised the Cabal build instructions on Hackage.
+
 -------------------------------------------------------------------
 Sun Feb 21 12:48:14 UTC 2021 - psimons@suse.com
 
diff --git a/ghc-dec.spec b/ghc-dec.spec
index 1f9c951..36b1472 100644
--- a/ghc-dec.spec
+++ b/ghc-dec.spec
@@ -1,7 +1,7 @@
 #
 # spec file for package ghc-dec
 #
-# Copyright (c) 2021 SUSE LLC
+# Copyright (c) 2022 SUSE LLC
 #
 # All modifications and additions to the file contributed by third parties
 # remain the property of their copyright owners, unless otherwise agreed
@@ -24,6 +24,7 @@ Summary:        Decidable propositions
 License:        BSD-3-Clause
 URL:            https://hackage.haskell.org/package/%{pkg_name}
 Source0:        https://hackage.haskell.org/package/%{pkg_name}-%{version}/%{pkg_name}-%{version}.tar.gz
+Source1:        https://hackage.haskell.org/package/%{pkg_name}-%{version}/revision/1.cabal#/%{pkg_name}.cabal
 BuildRequires:  ghc-Cabal-devel
 BuildRequires:  ghc-rpm-macros
 ExcludeArch:    %{ix86}
@@ -47,6 +48,7 @@ This package provides the Haskell %{pkg_name} library development files.
 
 %prep
 %autosetup -n %{pkg_name}-%{version}
+cp -p %{SOURCE1} %{pkg_name}.cabal
 
 %build
 %ghc_lib_build