diff --git a/.travis.yml b/.travis.yml
index b89c415a..dc3e557d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -41,6 +41,9 @@ matrix:
   - env: BUILD=cabal GHCVER=8.2.2 CABALVER=2.0 HAPPYVER=1.19.5 ALEXVER=3.1.7
     compiler: ": #GHC 8.2.2"
     addons: {apt: {packages: [cabal-install-2.0,ghc-8.2.2,happy-1.19.5,alex-3.1.7], sources: [hvr-ghc]}}
+  - env: BUILD=cabal GHCVER=8.4.3 CABALVER=2.2 HAPPYVER=1.19.5 ALEXVER=3.1.7
+    compiler: ": #GHC 8.4.3"
+    addons: {apt: {packages: [cabal-install-2.2,ghc-8.4.3,happy-1.19.5,alex-3.1.7], sources: [hvr-ghc]}}
 
   # Build with the newest GHC and cabal-install. This is an accepted failure,
   # see below.
@@ -54,15 +57,11 @@ matrix:
     compiler: ": #stack default"
     addons: {apt: {packages: [libgmp-dev]}}
 
-  - env: BUILD=stack ARGS="--resolver lts-7"
-    compiler: ": #stack 8.0.1"
-    addons: {apt: {packages: [libgmp-dev]}}
-
-  - env: BUILD=stack ARGS="--resolver lts-9"
+  - env: BUILD=stack ARGS="--stack-yaml stack-lts-9.yaml --resolver lts-9"
     compiler: ": #stack 8.0.2"
     addons: {apt: {packages: [libgmp-dev]}}
 
-  - env: BUILD=stack ARGS="--resolver lts-10"
+  - env: BUILD=stack ARGS="--stack-yaml stack-lts-11.yaml --resolver lts-11"
     compiler: ": #stack 8.2.2"
     addons: {apt: {packages: [libgmp-dev]}}
 
@@ -76,16 +75,11 @@ matrix:
     compiler: ": #stack default osx"
     os: osx
 
-  # malformed mach-o: load commands size (34184) > 32768)
-  #- env: BUILD=stack ARGS="--resolver lts-7"
-  #  compiler: ": #stack 8.0.1 osx"
-  #  os: osx
-
-  - env: BUILD=stack ARGS="--resolver lts-9"
+  - env: BUILD=stack ARGS="--stack-yaml stack-lts-9.yaml --resolver lts-9"
     compiler: ": #stack 8.0.2 osx"
     os: osx
 
-  - env: BUILD=stack ARGS="--resolver lts-10"
+  - env: BUILD=stack ARGS="--stack-yaml stack-lts-11.yaml --resolver lts-11"
     compiler: ": #stack 8.2.2 osx"
     os: osx
 
@@ -111,9 +105,9 @@ before_install:
 - |
   if [ `uname` = "Darwin" ]
   then
-    travis_retry curl --insecure -L https://www.stackage.org/stack/osx-x86_64 | tar xz --strip-components=1 --include '*/stack' -C ~/.local/bin
+    travis_retry curl --insecure -L https://get.haskellstack.org/stable/osx-x86_64.tar.gz | tar xz --strip-components=1 --include '*/stack' -C ~/.local/bin
   else
-    travis_retry curl -L https://www.stackage.org/stack/linux-x86_64 | tar xz --wildcards --strip-components=1 -C ~/.local/bin '*/stack'
+    travis_retry curl -L https://get.haskellstack.org/stable/linux-x86_64.tar.gz | tar xz --wildcards --strip-components=1 -C ~/.local/bin '*/stack'
   fi
 
   # Use the more reliable S3 mirror of Hackage
@@ -121,10 +115,6 @@ before_install:
   echo 'remote-repo: hackage.haskell.org:http://hackage.fpcomplete.com/' > $HOME/.cabal/config
   echo 'remote-repo-cache: $HOME/.cabal/packages' >> $HOME/.cabal/config
 
-  if [ "$CABALVER" != "1.16" ]
-  then
-    echo 'jobs: $ncpus' >> $HOME/.cabal/config
-  fi
 
 install:
 - echo "$(ghc --version) [$(ghc --print-project-git-commit-id 2> /dev/null || echo '?')]"
diff --git a/stack-lts-11.yaml b/stack-lts-11.yaml
new file mode 120000
index 00000000..2df91e0c
--- /dev/null
+++ b/stack-lts-11.yaml
@@ -0,0 +1 @@
+stack.yaml
\ No newline at end of file
diff --git a/stack-lts-9.yaml b/stack-lts-9.yaml
new file mode 100644
index 00000000..ad311b2e
--- /dev/null
+++ b/stack-lts-9.yaml
@@ -0,0 +1,37 @@
+resolver: lts-9.21
+packages:
+- ./yesod-core
+- ./yesod-static
+- ./yesod-persistent
+- ./yesod-newsfeed
+- ./yesod-form
+- ./yesod-auth
+- ./yesod-auth-oauth
+- ./yesod-sitemap
+- ./yesod-test
+- ./yesod-bin
+- ./yesod
+- ./yesod-eventsource
+- ./yesod-websockets
+extra-deps:
+- bsb-http-chunked-0.0.0.2@rev:0
+- conduit-1.3.0.2@rev:0
+- conduit-extra-1.3.0@rev:0
+- html-conduit-1.3.0@rev:0
+- http-client-0.5.12.1@rev:0
+- http-conduit-2.3.1@rev:0
+- monad-logger-0.3.28.5@rev:0
+- mono-traversable-1.0.8.1@rev:0
+- persistent-2.8.2@rev:0
+- persistent-sqlite-2.8.1.2@rev:0
+- project-template-0.2.0.1@rev:0
+- resourcet-1.2.1@rev:0
+- streaming-commons-0.2.0.0@rev:0
+- typed-process-0.2.2.0@rev:0
+- unliftio-0.2.7.0@rev:0
+- unliftio-core-0.1.1.0@rev:0
+- wai-extra-3.0.22.1@rev:0
+- wai-logger-2.3.2@rev:0
+- warp-3.2.22@rev:0
+- xml-conduit-1.8.0@rev:0
+- yaml-0.8.30@rev:0
diff --git a/stack.yaml b/stack.yaml
index 52ec0356..5789bb4b 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -1,46 +1,15 @@
-resolver: lts-8.12
+resolver: lts-11.10
 packages:
-  - ./yesod-core
-  - ./yesod-static
-  - ./yesod-persistent
-  - ./yesod-newsfeed
-  - ./yesod-form
-  - ./yesod-auth
-  - ./yesod-auth-oauth
-  - ./yesod-sitemap
-  - ./yesod-test
-  - ./yesod-bin
-  - ./yesod
-  - ./yesod-eventsource
-  - ./yesod-websockets
-extra-deps:
-- unliftio-core-0.1.1.0
-- unliftio-0.2.4.0
-- authenticate-1.3.4
-- typed-process-0.2.1.0
-- conduit-1.3.0
-- conduit-extra-1.3.0
-- persistent-2.8.0
-- resourcet-1.2.0
-- mono-traversable-1.0.8.1
-- yaml-0.8.28
-- project-template-0.2.0.1
-- xml-conduit-1.8.0
-- wai-extra-3.0.22.0
-- monad-logger-0.3.28.1
-- html-conduit-1.3.0
-- http-conduit-2.3.0
-- persistent-sqlite-2.8.0
-- cookie-0.4.3
-- gauge-0.2.1
-- basement-0.0.6
-- foundation-0.0.19
-- memory-0.14.14
-- simple-sendfile-0.2.27
-- aeson-1.2.4.0
-- http-client-0.5.10
-- http-client-tls-0.3.5.2
-- websockets-0.12.3.1
-- th-abstraction-0.2.6.0
-- persistent-template-2.5.3.1
-- th-lift-instances-0.1.11
+- ./yesod-core
+- ./yesod-static
+- ./yesod-persistent
+- ./yesod-newsfeed
+- ./yesod-form
+- ./yesod-auth
+- ./yesod-auth-oauth
+- ./yesod-sitemap
+- ./yesod-test
+- ./yesod-bin
+- ./yesod
+- ./yesod-eventsource
+- ./yesod-websockets