diff --git a/.travis.yml b/.travis.yml
index d251fb3d..d80c82e1 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,6 +4,8 @@
 #
 # For more information, see https://github.com/haskell-CI/haskell-ci
 #
+# version: 0.2.1
+#
 language: c
 dist: xenial
 
@@ -32,8 +34,8 @@ before_cache:
 
 matrix:
   include:
-    - compiler: "ghc-8.6.3"
-      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.4,ghc-8.6.3], sources: [hvr-ghc]}}
+    - compiler: "ghc-8.6.4"
+      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.4,ghc-8.6.4], sources: [hvr-ghc]}}
     - compiler: "ghc-8.4.4"
       addons: {apt: {packages: [ghc-ppa-tools,cabal-install-2.4,ghc-8.4.4], sources: [hvr-ghc]}}
     - compiler: "ghc-8.2.2"
@@ -43,8 +45,6 @@ matrix:
 
 before_install:
   - HC=/opt/ghc/bin/${CC}
-  - HCVER=$(echo "$TRAVIS_COMPILER" | sed 's/ghc-//')
-  - echo $HCVER
   - HCPKG=${HC/ghc/ghc-pkg}
   - unset CC
   - CABAL=/opt/ghc/bin/cabal
@@ -78,19 +78,19 @@ install:
   - "printf 'packages: \"servant-machines\"\\n' >> cabal.project"
   - "printf 'packages: \"servant-conduit\"\\n' >> cabal.project"
   - "printf 'packages: \"servant-pipes\"\\n' >> cabal.project"
-  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80603 ] ; then printf 'packages: \"doc/cookbook/basic-auth\"\\n' >> cabal.project ; fi"
-  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80603 ] ; then printf 'packages: \"doc/cookbook/curl-mock\"\\n' >> cabal.project ; fi"
-  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80603 ] ; then printf 'packages: \"doc/cookbook/basic-streaming\"\\n' >> cabal.project ; fi"
-  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80603 ] ; then printf 'packages: \"doc/cookbook/db-postgres-pool\"\\n' >> cabal.project ; fi"
-  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80603 ] ; then printf 'packages: \"doc/cookbook/db-sqlite-simple\"\\n' >> cabal.project ; fi"
-  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80603 ] ; then printf 'packages: \"doc/cookbook/file-upload\"\\n' >> cabal.project ; fi"
-  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80603 ] ; then printf 'packages: \"doc/cookbook/generic\"\\n' >> cabal.project ; fi"
-  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80603 ] ; then printf 'packages: \"doc/cookbook/https\"\\n' >> cabal.project ; fi"
-  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80603 ] ; then printf 'packages: \"doc/cookbook/pagination\"\\n' >> cabal.project ; fi"
-  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80603 ] ; then printf 'packages: \"doc/cookbook/testing\"\\n' >> cabal.project ; fi"
-  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80603 ] ; then printf 'packages: \"doc/cookbook/structuring-apis\"\\n' >> cabal.project ; fi"
-  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80603 ] ; then printf 'packages: \"doc/cookbook/using-custom-monad\"\\n' >> cabal.project ; fi"
-  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80603 ] ; then printf 'packages: \"doc/cookbook/using-free-client\"\\n' >> cabal.project ; fi"
+  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80604 ] ; then printf 'packages: \"doc/cookbook/basic-auth\"\\n' >> cabal.project ; fi"
+  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80604 ] ; then printf 'packages: \"doc/cookbook/curl-mock\"\\n' >> cabal.project ; fi"
+  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80604 ] ; then printf 'packages: \"doc/cookbook/basic-streaming\"\\n' >> cabal.project ; fi"
+  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80604 ] ; then printf 'packages: \"doc/cookbook/db-postgres-pool\"\\n' >> cabal.project ; fi"
+  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80604 ] ; then printf 'packages: \"doc/cookbook/db-sqlite-simple\"\\n' >> cabal.project ; fi"
+  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80604 ] ; then printf 'packages: \"doc/cookbook/file-upload\"\\n' >> cabal.project ; fi"
+  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80604 ] ; then printf 'packages: \"doc/cookbook/generic\"\\n' >> cabal.project ; fi"
+  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80604 ] ; then printf 'packages: \"doc/cookbook/https\"\\n' >> cabal.project ; fi"
+  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80604 ] ; then printf 'packages: \"doc/cookbook/pagination\"\\n' >> cabal.project ; fi"
+  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80604 ] ; then printf 'packages: \"doc/cookbook/testing\"\\n' >> cabal.project ; fi"
+  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80604 ] ; then printf 'packages: \"doc/cookbook/structuring-apis\"\\n' >> cabal.project ; fi"
+  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80604 ] ; then printf 'packages: \"doc/cookbook/using-custom-monad\"\\n' >> cabal.project ; fi"
+  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80604 ] ; then printf 'packages: \"doc/cookbook/using-free-client\"\\n' >> cabal.project ; fi"
   - "echo 'constraints: foundation >=0.0.14' >> cabal.project"
   - "echo 'constraints: memory <0.14.12 || >0.14.12' >> cabal.project"
   - "echo 'allow-newer: servant-quickcheck:servant' >> cabal.project"
@@ -156,19 +156,19 @@ script:
   - "printf 'packages: \"servant-machines-*/*.cabal\"\\n' >> cabal.project"
   - "printf 'packages: \"servant-conduit-*/*.cabal\"\\n' >> cabal.project"
   - "printf 'packages: \"servant-pipes-*/*.cabal\"\\n' >> cabal.project"
-  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80603 ] ; then printf 'packages: \"cookbook-basic-auth-*/*.cabal\"\\n' >> cabal.project ; fi"
-  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80603 ] ; then printf 'packages: \"cookbook-curl-mock-*/*.cabal\"\\n' >> cabal.project ; fi"
-  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80603 ] ; then printf 'packages: \"cookbook-basic-streaming-*/*.cabal\"\\n' >> cabal.project ; fi"
-  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80603 ] ; then printf 'packages: \"cookbook-db-postgres-pool-*/*.cabal\"\\n' >> cabal.project ; fi"
-  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80603 ] ; then printf 'packages: \"cookbook-db-sqlite-simple-*/*.cabal\"\\n' >> cabal.project ; fi"
-  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80603 ] ; then printf 'packages: \"cookbook-file-upload-*/*.cabal\"\\n' >> cabal.project ; fi"
-  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80603 ] ; then printf 'packages: \"cookbook-generic-*/*.cabal\"\\n' >> cabal.project ; fi"
-  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80603 ] ; then printf 'packages: \"cookbook-https-*/*.cabal\"\\n' >> cabal.project ; fi"
-  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80603 ] ; then printf 'packages: \"cookbook-pagination-*/*.cabal\"\\n' >> cabal.project ; fi"
-  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80603 ] ; then printf 'packages: \"cookbook-testing-*/*.cabal\"\\n' >> cabal.project ; fi"
-  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80603 ] ; then printf 'packages: \"cookbook-structuring-apis-*/*.cabal\"\\n' >> cabal.project ; fi"
-  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80603 ] ; then printf 'packages: \"cookbook-using-custom-monad-*/*.cabal\"\\n' >> cabal.project ; fi"
-  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80603 ] ; then printf 'packages: \"cookbook-using-free-client-*/*.cabal\"\\n' >> cabal.project ; fi"
+  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80604 ] ; then printf 'packages: \"cookbook-basic-auth-*/*.cabal\"\\n' >> cabal.project ; fi"
+  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80604 ] ; then printf 'packages: \"cookbook-curl-mock-*/*.cabal\"\\n' >> cabal.project ; fi"
+  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80604 ] ; then printf 'packages: \"cookbook-basic-streaming-*/*.cabal\"\\n' >> cabal.project ; fi"
+  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80604 ] ; then printf 'packages: \"cookbook-db-postgres-pool-*/*.cabal\"\\n' >> cabal.project ; fi"
+  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80604 ] ; then printf 'packages: \"cookbook-db-sqlite-simple-*/*.cabal\"\\n' >> cabal.project ; fi"
+  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80604 ] ; then printf 'packages: \"cookbook-file-upload-*/*.cabal\"\\n' >> cabal.project ; fi"
+  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80604 ] ; then printf 'packages: \"cookbook-generic-*/*.cabal\"\\n' >> cabal.project ; fi"
+  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80604 ] ; then printf 'packages: \"cookbook-https-*/*.cabal\"\\n' >> cabal.project ; fi"
+  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80604 ] ; then printf 'packages: \"cookbook-pagination-*/*.cabal\"\\n' >> cabal.project ; fi"
+  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80604 ] ; then printf 'packages: \"cookbook-testing-*/*.cabal\"\\n' >> cabal.project ; fi"
+  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80604 ] ; then printf 'packages: \"cookbook-structuring-apis-*/*.cabal\"\\n' >> cabal.project ; fi"
+  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80604 ] ; then printf 'packages: \"cookbook-using-custom-monad-*/*.cabal\"\\n' >> cabal.project ; fi"
+  - "if [ $HCNUMVER -eq 80404 ]  ||  [ $HCNUMVER -eq 80604 ] ; then printf 'packages: \"cookbook-using-free-client-*/*.cabal\"\\n' >> cabal.project ; fi"
   - "echo 'constraints: foundation >=0.0.14' >> cabal.project"
   - "echo 'constraints: memory <0.14.12 || >0.14.12' >> cabal.project"
   - "echo 'allow-newer: servant-quickcheck:servant' >> cabal.project"
diff --git a/doc/cookbook/basic-auth/basic-auth.cabal b/doc/cookbook/basic-auth/basic-auth.cabal
index edefd31e..190f4151 100644
--- a/doc/cookbook/basic-auth/basic-auth.cabal
+++ b/doc/cookbook/basic-auth/basic-auth.cabal
@@ -8,7 +8,7 @@ author:              Servant Contributors
 maintainer:          haskell-servant-maintainers@googlegroups.com
 build-type:          Simple
 cabal-version:       >=1.10
-tested-with:         GHC==8.4.4, GHC==8.6.3
+tested-with:         GHC==8.4.4, GHC==8.6.4
 
 executable cookbook-basic-auth
   main-is:             BasicAuth.lhs
diff --git a/doc/cookbook/basic-streaming/basic-streaming.cabal b/doc/cookbook/basic-streaming/basic-streaming.cabal
index a81cf04d..61ddbbd2 100644
--- a/doc/cookbook/basic-streaming/basic-streaming.cabal
+++ b/doc/cookbook/basic-streaming/basic-streaming.cabal
@@ -8,7 +8,7 @@ author:              Servant Contributors
 maintainer:          haskell-servant-maintainers@googlegroups.com
 build-type:          Simple
 cabal-version:       >=1.10
-tested-with:         GHC==8.4.4, GHC==8.6.3
+tested-with:         GHC==8.4.4, GHC==8.6.4
 
 executable cookbook-basic-streaming
   main-is:             Streaming.lhs
diff --git a/doc/cookbook/curl-mock/curl-mock.cabal b/doc/cookbook/curl-mock/curl-mock.cabal
index f519c4f6..ad38d93b 100644
--- a/doc/cookbook/curl-mock/curl-mock.cabal
+++ b/doc/cookbook/curl-mock/curl-mock.cabal
@@ -8,7 +8,7 @@ author:              Servant Contributors
 maintainer:          haskell-servant-maintainers@googlegroups.com
 build-type:          Simple
 cabal-version:       >=1.10
-tested-with:         GHC==8.4.4, GHC==8.6.3
+tested-with:         GHC==8.4.4, GHC==8.6.4
 
 executable cookbock-curl-mock
   main-is:             CurlMock.lhs
diff --git a/doc/cookbook/db-postgres-pool/db-postgres-pool.cabal b/doc/cookbook/db-postgres-pool/db-postgres-pool.cabal
index 86dc4154..884d110c 100644
--- a/doc/cookbook/db-postgres-pool/db-postgres-pool.cabal
+++ b/doc/cookbook/db-postgres-pool/db-postgres-pool.cabal
@@ -8,7 +8,7 @@ author:              Servant Contributors
 maintainer:          haskell-servant-maintainers@googlegroups.com
 build-type:          Simple
 cabal-version:       >=1.10
-tested-with:         GHC==8.4.4, GHC==8.6.3
+tested-with:         GHC==8.4.4, GHC==8.6.4
 
 executable cookbook-db-postgres-pool
   main-is:             PostgresPool.lhs
diff --git a/doc/cookbook/db-sqlite-simple/db-sqlite-simple.cabal b/doc/cookbook/db-sqlite-simple/db-sqlite-simple.cabal
index 24e5da52..5291537d 100644
--- a/doc/cookbook/db-sqlite-simple/db-sqlite-simple.cabal
+++ b/doc/cookbook/db-sqlite-simple/db-sqlite-simple.cabal
@@ -8,7 +8,7 @@ author:              Servant Contributors
 maintainer:          haskell-servant-maintainers@googlegroups.com
 build-type:          Simple
 cabal-version:       >=1.10
-tested-with:         GHC==8.4.4, GHC==8.6.3
+tested-with:         GHC==8.4.4, GHC==8.6.4
 
 executable cookbook-db-sqlite-simple
   main-is:             DBConnection.lhs
diff --git a/doc/cookbook/file-upload/file-upload.cabal b/doc/cookbook/file-upload/file-upload.cabal
index 6d35539f..76df2951 100644
--- a/doc/cookbook/file-upload/file-upload.cabal
+++ b/doc/cookbook/file-upload/file-upload.cabal
@@ -8,7 +8,7 @@ author:              Servant Contributors
 maintainer:          haskell-servant-maintainers@googlegroups.com
 build-type:          Simple
 cabal-version:       >=1.10
-tested-with:         GHC==8.4.4, GHC==8.6.3
+tested-with:         GHC==8.4.4, GHC==8.6.4
 
 executable cookbook-file-upload
   main-is:             FileUpload.lhs
diff --git a/doc/cookbook/generic/generic.cabal b/doc/cookbook/generic/generic.cabal
index 71e02c80..7ec588ee 100644
--- a/doc/cookbook/generic/generic.cabal
+++ b/doc/cookbook/generic/generic.cabal
@@ -8,7 +8,7 @@ author:              Servant Contributors
 maintainer:          haskell-servant-maintainers@googlegroups.com
 build-type:          Simple
 cabal-version:       >=1.10
-tested-with:         GHC==8.4.4, GHC==8.6.3
+tested-with:         GHC==8.4.4, GHC==8.6.4
 
 executable cookbook-using-custom-monad
   main-is:             Generic.lhs
diff --git a/doc/cookbook/hoist-server-with-context/hoist-server-with-context.cabal b/doc/cookbook/hoist-server-with-context/hoist-server-with-context.cabal
index b06cc01e..49c8852b 100644
--- a/doc/cookbook/hoist-server-with-context/hoist-server-with-context.cabal
+++ b/doc/cookbook/hoist-server-with-context/hoist-server-with-context.cabal
@@ -11,7 +11,7 @@ maintainer:          haskell-servant-maintainers@googlegroups.com
 category:            Servant
 build-type:          Simple
 cabal-version:       >=1.10
-tested-with:         GHC==8.4.4, GHC==8.6.3
+tested-with:         GHC==8.4.4, GHC==8.6.4
 
 executable cookbook-hoist-server-with-context
   main-is:             HoistServerWithContext.lhs
diff --git a/doc/cookbook/https/https.cabal b/doc/cookbook/https/https.cabal
index 670a0739..a6f235de 100644
--- a/doc/cookbook/https/https.cabal
+++ b/doc/cookbook/https/https.cabal
@@ -8,7 +8,7 @@ author:              Servant Contributors
 maintainer:          haskell-servant-maintainers@googlegroups.com
 build-type:          Simple
 cabal-version:       >=1.10
-tested-with:         GHC==8.4.4, GHC==8.6.3
+tested-with:         GHC==8.4.4, GHC==8.6.4
 
 executable cookbook-https
   main-is:             Https.lhs
diff --git a/doc/cookbook/jwt-and-basic-auth/jwt-and-basic-auth.cabal b/doc/cookbook/jwt-and-basic-auth/jwt-and-basic-auth.cabal
index a83933e2..705e27e8 100644
--- a/doc/cookbook/jwt-and-basic-auth/jwt-and-basic-auth.cabal
+++ b/doc/cookbook/jwt-and-basic-auth/jwt-and-basic-auth.cabal
@@ -11,7 +11,7 @@ maintainer:          haskell-servant-maintainers@googlegroups.com
 category:            Servant
 build-type:          Simple
 cabal-version:       >=1.10
-tested-with:         GHC==8.4.4, GHC==8.6.3
+tested-with:         GHC==8.4.4, GHC==8.6.4
 
 executable cookbook-jwt-and-basic-auth
   main-is:             JWTAndBasicAuth.lhs
diff --git a/doc/cookbook/pagination/pagination.cabal b/doc/cookbook/pagination/pagination.cabal
index 0c16debe..d7c15961 100644
--- a/doc/cookbook/pagination/pagination.cabal
+++ b/doc/cookbook/pagination/pagination.cabal
@@ -8,7 +8,7 @@ author:              Servant Contributors
 maintainer:          haskell-servant-maintainers@googlegroups.com
 build-type:          Simple
 cabal-version:       >=1.10
-tested-with:         GHC==8.4.4, GHC==8.6.3
+tested-with:         GHC==8.4.4, GHC==8.6.4
 
 executable cookbook-pagination
   main-is:             Pagination.lhs
diff --git a/doc/cookbook/sentry/sentry.cabal b/doc/cookbook/sentry/sentry.cabal
index 7096e2eb..716b45a9 100644
--- a/doc/cookbook/sentry/sentry.cabal
+++ b/doc/cookbook/sentry/sentry.cabal
@@ -8,7 +8,7 @@ author:              Servant Contributors
 maintainer:          haskell-servant-maintainers@googlegroups.com
 build-type:          Simple
 cabal-version:       >=1.10
-tested-with:         GHC==8.4.4, GHC==8.6.3
+tested-with:         GHC==8.4.4, GHC==8.6.4
 
 executable cookbook-sentry
   main-is:             Sentry.lhs
diff --git a/doc/cookbook/structuring-apis/structuring-apis.cabal b/doc/cookbook/structuring-apis/structuring-apis.cabal
index eb6d7756..d99413bd 100644
--- a/doc/cookbook/structuring-apis/structuring-apis.cabal
+++ b/doc/cookbook/structuring-apis/structuring-apis.cabal
@@ -8,7 +8,7 @@ author:              Servant Contributors
 maintainer:          haskell-servant-maintainers@googlegroups.com
 build-type:          Simple
 cabal-version:       >=1.10
-tested-with:         GHC==8.4.4, GHC==8.6.3
+tested-with:         GHC==8.4.4, GHC==8.6.4
 
 executable cookbook-structuring-apis
   main-is:             StructuringApis.lhs
diff --git a/doc/cookbook/testing/testing.cabal b/doc/cookbook/testing/testing.cabal
index 2bfbd73f..3863c8d6 100644
--- a/doc/cookbook/testing/testing.cabal
+++ b/doc/cookbook/testing/testing.cabal
@@ -10,7 +10,7 @@ maintainer:          haskell-servant-maintainers@googlegroups.com
 category:            Servant
 build-type:          Simple
 cabal-version:       >=1.10
-tested-with:         GHC==8.4.4, GHC==8.6.3
+tested-with:         GHC==8.4.4, GHC==8.6.4
 
 executable cookbook-testing
   main-is:             Testing.lhs
diff --git a/doc/cookbook/using-custom-monad/using-custom-monad.cabal b/doc/cookbook/using-custom-monad/using-custom-monad.cabal
index 7fefa489..8532ed5e 100644
--- a/doc/cookbook/using-custom-monad/using-custom-monad.cabal
+++ b/doc/cookbook/using-custom-monad/using-custom-monad.cabal
@@ -8,7 +8,7 @@ author:              Servant Contributors
 maintainer:          haskell-servant-maintainers@googlegroups.com
 build-type:          Simple
 cabal-version:       >=1.10
-tested-with:         GHC==8.4.4, GHC==8.6.3
+tested-with:         GHC==8.4.4, GHC==8.6.4
 
 executable cookbook-using-custom-monad
   main-is:             UsingCustomMonad.lhs
diff --git a/doc/cookbook/using-free-client/using-free-client.cabal b/doc/cookbook/using-free-client/using-free-client.cabal
index 7fd053c2..80a2c4b3 100644
--- a/doc/cookbook/using-free-client/using-free-client.cabal
+++ b/doc/cookbook/using-free-client/using-free-client.cabal
@@ -8,7 +8,7 @@ author:              Servant Contributors
 maintainer:          haskell-servant-maintainers@googlegroups.com
 build-type:          Simple
 cabal-version:       >=1.10
-tested-with:         GHC==8.4.4, GHC==8.6.3
+tested-with:         GHC==8.4.4, GHC==8.6.4
 
 executable cookbook-using-free-client
   main-is:             UsingFreeClient.lhs
diff --git a/doc/tutorial/tutorial.cabal b/doc/tutorial/tutorial.cabal
index 2f0edc33..a1d2f5c9 100644
--- a/doc/tutorial/tutorial.cabal
+++ b/doc/tutorial/tutorial.cabal
@@ -16,7 +16,7 @@ tested-with:
   GHC==8.0.2
   GHC==8.2.2
   GHC==8.4.4
-  GHC==8.6.3
+  GHC==8.6.4
 extra-source-files:
   static/index.html
   static/ui.js
diff --git a/servant-client-core/servant-client-core.cabal b/servant-client-core/servant-client-core.cabal
index af2b8514..61d6e38e 100644
--- a/servant-client-core/servant-client-core.cabal
+++ b/servant-client-core/servant-client-core.cabal
@@ -20,7 +20,7 @@ tested-with:
   GHC ==8.0.2
    || ==8.2.2
    || ==8.4.4
-   || ==8.6.3
+   || ==8.6.4
 
 extra-source-files:
   CHANGELOG.md
diff --git a/servant-client/servant-client.cabal b/servant-client/servant-client.cabal
index 9dc92c47..73ee378b 100644
--- a/servant-client/servant-client.cabal
+++ b/servant-client/servant-client.cabal
@@ -24,7 +24,7 @@ tested-with:
   GHC ==8.0.2
    || ==8.2.2
    || ==8.4.4
-   || ==8.6.3
+   || ==8.6.4
 
 extra-source-files:
   CHANGELOG.md
diff --git a/servant-conduit/servant-conduit.cabal b/servant-conduit/servant-conduit.cabal
index 8a7535cb..7c671235 100644
--- a/servant-conduit/servant-conduit.cabal
+++ b/servant-conduit/servant-conduit.cabal
@@ -21,7 +21,7 @@ tested-with:
   GHC ==8.0.2
    || ==8.2.2
    || ==8.4.4
-   || ==8.6.3
+   || ==8.6.4
 
 extra-source-files:
   CHANGELOG.md
diff --git a/servant-docs/servant-docs.cabal b/servant-docs/servant-docs.cabal
index 38923afd..8acc49e8 100644
--- a/servant-docs/servant-docs.cabal
+++ b/servant-docs/servant-docs.cabal
@@ -24,7 +24,7 @@ tested-with:
   GHC ==8.0.2
    || ==8.2.2
    || ==8.4.4
-   || ==8.6.3
+   || ==8.6.4
 
 extra-source-files:
   CHANGELOG.md
diff --git a/servant-foreign/servant-foreign.cabal b/servant-foreign/servant-foreign.cabal
index 23f40dde..1fb38d6d 100644
--- a/servant-foreign/servant-foreign.cabal
+++ b/servant-foreign/servant-foreign.cabal
@@ -26,7 +26,7 @@ tested-with:
   GHC ==8.0.2
    || ==8.2.2
    || ==8.4.4
-   || ==8.6.3
+   || ==8.6.4
 
 extra-source-files:
   CHANGELOG.md
diff --git a/servant-http-streams/servant-http-streams.cabal b/servant-http-streams/servant-http-streams.cabal
index 9c6a6917..12c4d1bc 100644
--- a/servant-http-streams/servant-http-streams.cabal
+++ b/servant-http-streams/servant-http-streams.cabal
@@ -24,7 +24,7 @@ tested-with:
   GHC ==8.0.2
    || ==8.2.2
    || ==8.4.4
-   || ==8.6.3
+   || ==8.6.4
 
 extra-source-files:
   CHANGELOG.md
diff --git a/servant-machines/servant-machines.cabal b/servant-machines/servant-machines.cabal
index ba22d185..2d09ba48 100644
--- a/servant-machines/servant-machines.cabal
+++ b/servant-machines/servant-machines.cabal
@@ -21,7 +21,7 @@ tested-with:
   GHC ==8.0.2
    || ==8.2.2
    || ==8.4.4
-   || ==8.6.3
+   || ==8.6.4
 
 extra-source-files:
   CHANGELOG.md
diff --git a/servant-pipes/servant-pipes.cabal b/servant-pipes/servant-pipes.cabal
index eb72d739..bd55a9fe 100644
--- a/servant-pipes/servant-pipes.cabal
+++ b/servant-pipes/servant-pipes.cabal
@@ -21,7 +21,7 @@ tested-with:
   GHC ==8.0.2
    || ==8.2.2
    || ==8.4.4
-   || ==8.6.3
+   || ==8.6.4
 
 extra-source-files:
   CHANGELOG.md
diff --git a/servant-server/servant-server.cabal b/servant-server/servant-server.cabal
index db5e9cbf..ee86ac7f 100644
--- a/servant-server/servant-server.cabal
+++ b/servant-server/servant-server.cabal
@@ -27,7 +27,7 @@ tested-with:
   GHC ==8.0.2
    || ==8.2.2
    || ==8.4.4
-   || ==8.6.3
+   || ==8.6.4
 
 extra-source-files:
   CHANGELOG.md
diff --git a/servant/servant.cabal b/servant/servant.cabal
index 094fd5c9..8238543b 100644
--- a/servant/servant.cabal
+++ b/servant/servant.cabal
@@ -24,7 +24,7 @@ tested-with:
   GHC ==8.0.2
    || ==8.2.2
    || ==8.4.4
-   || ==8.6.3
+   || ==8.6.4
 
 extra-source-files:
   CHANGELOG.md