diff --git a/hledger-lib/hledger-lib.cabal b/hledger-lib/hledger-lib.cabal
index 3cabd8d7b..bf70c7e1a 100644
--- a/hledger-lib/hledger-lib.cabal
+++ b/hledger-lib/hledger-lib.cabal
@@ -4,7 +4,7 @@ cabal-version: 1.12
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: d44cc48a2f9dc087afe19992824ce4e95ddf82662880f81963eb6389a5ef4a83
+-- hash: cf0e219278c663cf046db556525050092c383724e703e70b43ed174a0cc146b9
 
 name:           hledger-lib
 version:        1.15.99
@@ -144,9 +144,6 @@ library
     , transformers >=0.2
     , uglymemo
     , utf8-string >=0.3.5
-  if (!impl(ghc >= 8.0))
-    build-depends:
-        semigroups ==0.18.*
   default-language: Haskell2010
 
 test-suite doctests
@@ -200,9 +197,6 @@ test-suite doctests
     , uglymemo
     , utf8-string >=0.3.5
   buildable: True
-  if (!impl(ghc >= 8.0))
-    build-depends:
-        semigroups ==0.18.*
   if (impl(ghc < 8.2))
     buildable: False
   default-language: Haskell2010
@@ -258,7 +252,4 @@ test-suite unittests
     , uglymemo
     , utf8-string >=0.3.5
   buildable: True
-  if (!impl(ghc >= 8.0))
-    build-depends:
-        semigroups ==0.18.*
   default-language: Haskell2010
diff --git a/hledger-lib/package.yaml b/hledger-lib/package.yaml
index b5c464372..e2ff724d3 100644
--- a/hledger-lib/package.yaml
+++ b/hledger-lib/package.yaml
@@ -85,11 +85,6 @@ dependencies:
 #- system-filepath
 #- trifecta >=0.91
 
-when:
-- condition: (!impl(ghc >= 8.0))
-  dependencies:
-  - semigroups == 0.18.*
-
 ghc-options:
 - -Wall
 - -fno-warn-unused-do-bind
diff --git a/hledger-ui/hledger-ui.cabal b/hledger-ui/hledger-ui.cabal
index bb44c8775..db32bc667 100644
--- a/hledger-ui/hledger-ui.cabal
+++ b/hledger-ui/hledger-ui.cabal
@@ -4,7 +4,7 @@ cabal-version: 1.12
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 5758671e5b0acb2bf4a05c9dd25f367c82d96e8bfe00e1f5406ae45e063e18cc
+-- hash: 70c14c6ae6d92c6f36da43bfdf255eae87982e3c0153d84669670f53f547473e
 
 name:           hledger-ui
 version:        1.15.99
diff --git a/hledger-web/hledger-web.cabal b/hledger-web/hledger-web.cabal
index cd9dfc397..57812021a 100644
--- a/hledger-web/hledger-web.cabal
+++ b/hledger-web/hledger-web.cabal
@@ -4,7 +4,7 @@ cabal-version: 1.12
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 099ba14e8b1770fb6354f5b6bf32275b52f20dcbafbf17f71515b09523077db4
+-- hash: d10d0a165f35e7a12aaac67eb660cdbbda833c35f0177281c280e18e9083fc16
 
 name:           hledger-web
 version:        1.15.99
@@ -150,7 +150,7 @@ library
       Paths_hledger_web
   hs-source-dirs:
       ./.
-  ghc-options: -Wall -fwarn-tabs
+  ghc-options: -Wall -fwarn-tabs -Wcompat -Wincomplete-uni-patterns -Wincomplete-record-updates -Wredundant-constraints
   cpp-options: -DVERSION="1.15.99"
   build-depends:
       Decimal
@@ -190,20 +190,14 @@ library
     , wai-handler-launch >=1.3
     , warp
     , yaml
+    , yesod >=1.4 && <1.7
+    , yesod-core >=1.4 && <1.7
+    , yesod-form >=1.4 && <1.7
+    , yesod-static >=1.4 && <1.7
   if (flag(dev)) || (flag(library-only))
     cpp-options: -DDEVELOPMENT
   if flag(dev)
     ghc-options: -O0
-  if impl(ghc >=8)
-    ghc-options: -Wcompat -Wincomplete-uni-patterns -Wincomplete-record-updates -Wredundant-constraints
-  if os(darwin) && impl(ghc < 8.0)
-    buildable: False
-  else
-    build-depends:
-        yesod >=1.4 && <1.7
-      , yesod-core >=1.4 && <1.7
-      , yesod-form >=1.4 && <1.7
-      , yesod-static >=1.4 && <1.7
   default-language: Haskell2010
 
 executable hledger-web
@@ -212,7 +206,7 @@ executable hledger-web
       Paths_hledger_web
   hs-source-dirs:
       app
-  ghc-options: -Wall -fwarn-tabs
+  ghc-options: -Wall -fwarn-tabs -Wcompat -Wincomplete-uni-patterns -Wincomplete-record-updates -Wredundant-constraints
   cpp-options: -DVERSION="1.15.99"
   build-depends:
       base
@@ -221,12 +215,8 @@ executable hledger-web
     cpp-options: -DDEVELOPMENT
   if flag(dev)
     ghc-options: -O0
-  if impl(ghc >=8)
-    ghc-options: -Wcompat -Wincomplete-uni-patterns -Wincomplete-record-updates -Wredundant-constraints
   if flag(library-only)
     buildable: False
   if flag(threaded)
     ghc-options: -threaded
-  if os(darwin) && impl(ghc < 8.0)
-    buildable: False
   default-language: Haskell2010
diff --git a/hledger-web/package.yaml b/hledger-web/package.yaml
index 22fcb2bf1..c65175e75 100644
--- a/hledger-web/package.yaml
+++ b/hledger-web/package.yaml
@@ -61,6 +61,10 @@ flags:
 ghc-options:
 - -Wall
 - -fwarn-tabs
+- -Wcompat
+- -Wincomplete-uni-patterns
+- -Wincomplete-record-updates
+- -Wredundant-constraints
 
 when:
 - condition: (flag(dev)) || (flag(library-only))
@@ -70,12 +74,6 @@ when:
 # 'ghc-options: -O0' is not needed. Use the --disable-optimization configure flag.
 - condition: flag(dev)
   ghc-options: -O0
-- condition: impl(ghc >=8)
-  ghc-options:
-  - -Wcompat
-  - -Wincomplete-uni-patterns
-  - -Wincomplete-record-updates
-  - -Wredundant-constraints
 
 library:
   source-dirs: .
@@ -136,17 +134,10 @@ library:
   - wai-cors
   - warp
   - yaml
-  # on mac Sierra or greater, ghc 7 will fail to build yesod; don't try
-  when:
-    - condition: os(darwin) && impl(ghc < 8.0)
-      then:
-        buildable: false
-      else:
-        dependencies:
-        - yesod        >=1.4 && < 1.7
-        - yesod-core   >=1.4 && < 1.7
-        - yesod-form   >=1.4 && < 1.7
-        - yesod-static >=1.4 && < 1.7
+  - yesod        >=1.4 && < 1.7
+  - yesod-core   >=1.4 && < 1.7
+  - yesod-form   >=1.4 && < 1.7
+  - yesod-static >=1.4 && < 1.7
 
 executables:
   hledger-web:
@@ -161,8 +152,6 @@ executables:
       buildable: false
     - condition: flag(threaded)
       ghc-options: -threaded
-    - condition: os(darwin) && impl(ghc < 8.0)
-      buildable: false
 
 # 2018/06 not building and not testing anything useful, disabled for now
 # tests:
diff --git a/hledger/hledger.cabal b/hledger/hledger.cabal
index 8838aafeb..7f84332f4 100644
--- a/hledger/hledger.cabal
+++ b/hledger/hledger.cabal
@@ -4,7 +4,7 @@ cabal-version: 1.12
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 75d5808338f41ef33fa1176ecc21a128e86171392a9526870a2bccd75adabb7c
+-- hash: 2caa4c7971b9bba457b966879bd8d4037f556ae2691e2c214a7c38a2140a18d9
 
 name:           hledger
 version:        1.15.99