diff --git a/hledger-api/hledger-api.cabal b/hledger-api/hledger-api.cabal
index 3c3a667e4..51c341eb6 100644
--- a/hledger-api/hledger-api.cabal
+++ b/hledger-api/hledger-api.cabal
@@ -1,8 +1,8 @@
--- This file has been generated from package.yaml by hpack version 0.20.0.
+-- This file has been generated from package.yaml by hpack version 0.21.2.
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 66e47e69f42abc82efc4dd262f42bffb6292f387520b5b75b6dd71ca0991128a
+-- hash: c30ba28c4fb8d8763b4cb710dc6aa957af07ff28f34e9605997b798d33ad7e18
 
 name:           hledger-api
 version:        1.5.99
@@ -48,7 +48,7 @@ executable hledger-api
   build-depends:
       Decimal
     , aeson
-    , base >=4.8 && <5
+    , base >=4.8 && <4.12
     , bytestring
     , containers
     , docopt
diff --git a/hledger-lib/hledger-lib.cabal b/hledger-lib/hledger-lib.cabal
index ffe36a385..1cb7c5695 100644
--- a/hledger-lib/hledger-lib.cabal
+++ b/hledger-lib/hledger-lib.cabal
@@ -2,7 +2,7 @@
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: cbe598ce4858fbf5dde16925499a85ff389700d3504666b582be23a366739bbd
+-- hash: 916d92693555f9b8362107e6b607319726dac39eb253d530485abf0dd0abcdeb
 
 name:           hledger-lib
 version:        1.5.99
@@ -103,7 +103,7 @@ library
     , HUnit
     , ansi-terminal >=0.6.2.3
     , array
-    , base >=4.8 && <5
+    , base >=4.8 && <4.12
     , base-compat >=0.8.1
     , blaze-markup >=0.5.1
     , bytestring
@@ -194,7 +194,7 @@ test-suite doctests
     , HUnit
     , ansi-terminal >=0.6.2.3
     , array
-    , base >=4.8 && <5
+    , base >=4.8 && <4.12
     , base-compat >=0.8.1
     , blaze-markup >=0.5.1
     , bytestring
@@ -285,7 +285,7 @@ test-suite easytests
     , HUnit
     , ansi-terminal >=0.6.2.3
     , array
-    , base >=4.8 && <5
+    , base >=4.8 && <4.12
     , base-compat >=0.8.1
     , blaze-markup >=0.5.1
     , bytestring
@@ -377,7 +377,7 @@ test-suite hunittests
     , HUnit
     , ansi-terminal >=0.6.2.3
     , array
-    , base >=4.8 && <5
+    , base >=4.8 && <4.12
     , base-compat >=0.8.1
     , blaze-markup >=0.5.1
     , bytestring
diff --git a/hledger-ui/hledger-ui.cabal b/hledger-ui/hledger-ui.cabal
index 89bf32d1f..65f4e66df 100644
--- a/hledger-ui/hledger-ui.cabal
+++ b/hledger-ui/hledger-ui.cabal
@@ -1,8 +1,8 @@
--- This file has been generated from package.yaml by hpack version 0.20.0.
+-- This file has been generated from package.yaml by hpack version 0.21.2.
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: f4bc380b9cd5f49af0f1534f8978ef8cd5f209c77fa81ca93444f0f8858ab49b
+-- hash: aeeb8e437253815b541ebabaa1d968a0f58b3860e9b33c92639bb8ad87652c44
 
 name:           hledger-ui
 version:        1.5.99
@@ -55,7 +55,7 @@ executable hledger-ui
       HUnit
     , ansi-terminal >=0.6.2.3
     , async
-    , base >=4.8 && <5
+    , base >=4.8 && <4.12
     , base-compat >=0.8.1
     , cmdargs >=0.8
     , containers
diff --git a/hledger-web/hledger-web.cabal b/hledger-web/hledger-web.cabal
index 6d96ffc7d..5d66ed443 100644
--- a/hledger-web/hledger-web.cabal
+++ b/hledger-web/hledger-web.cabal
@@ -1,8 +1,8 @@
--- This file has been generated from package.yaml by hpack version 0.20.0.
+-- This file has been generated from package.yaml by hpack version 0.21.2.
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 36b5bb0fe92c72e4e34972aecc9e4bf6146ba5335af16843402857120b506267
+-- hash: 6ac6cd9a90e98fd627995426fa393603f35dca08c92fc04aa7d07a9265925172
 
 name:           hledger-web
 version:        1.5.99
@@ -125,7 +125,7 @@ library
   cpp-options: -DVERSION="1.5.99"
   build-depends:
       HUnit
-    , base >=4.8 && <5
+    , base >=4.8 && <4.12
     , base-compat >=0.8.1
     , blaze-html
     , blaze-markup
@@ -193,7 +193,7 @@ executable hledger-web
   cpp-options: -DVERSION="1.5.99"
   build-depends:
       HUnit
-    , base >=4.8 && <5
+    , base >=4.8 && <4.12
     , base-compat >=0.8.1
     , blaze-html
     , blaze-markup
@@ -250,7 +250,7 @@ test-suite test
   cpp-options: -DVERSION="1.5.99"
   build-depends:
       HUnit
-    , base >=4.8 && <5
+    , base >=4.8 && <4.12
     , base-compat >=0.8.1
     , blaze-html
     , blaze-markup
diff --git a/hledger/hledger.cabal b/hledger/hledger.cabal
index 7dc0e316f..7251e84b3 100644
--- a/hledger/hledger.cabal
+++ b/hledger/hledger.cabal
@@ -1,8 +1,8 @@
--- This file has been generated from package.yaml by hpack version 0.20.0.
+-- This file has been generated from package.yaml by hpack version 0.21.2.
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 4f6f5987e53fdedbadc89cb204e1c986bd36c663a71808e642eefe15edebe72f
+-- hash: f8f9cb9d2b75d91e5ec746b32d1b0bb664b7914e1e578ae8a63e3ca0b39bbdfd
 
 name:           hledger
 version:        1.5.99
@@ -84,7 +84,7 @@ library
     , Diff
     , HUnit
     , ansi-terminal >=0.6.2.3
-    , base >=4.8 && <5
+    , base >=4.8 && <4.12
     , base-compat >=0.8.1
     , bytestring
     , cmdargs >=0.10
@@ -166,7 +166,7 @@ executable hledger
       Decimal
     , HUnit
     , ansi-terminal >=0.6.2.3
-    , base >=4.8 && <5
+    , base >=4.8 && <4.12
     , base-compat >=0.8.1
     , bytestring
     , cmdargs >=0.10
@@ -218,7 +218,7 @@ test-suite test
       Decimal
     , HUnit
     , ansi-terminal >=0.6.2.3
-    , base >=4.8 && <5
+    , base >=4.8 && <4.12
     , base-compat >=0.8.1
     , bytestring
     , cmdargs >=0.10
@@ -267,7 +267,7 @@ benchmark bench
   ghc-options: -Wall -fno-warn-unused-do-bind -fno-warn-name-shadowing -fno-warn-missing-signatures -fno-warn-type-defaults -fno-warn-orphans
   build-depends:
       ansi-terminal >=0.6.2.3
-    , base >=4.8 && <5
+    , base >=4.8 && <4.12
     , base-compat >=0.8.1
     , criterion
     , directory