diff --git a/circle.yml b/circle.yml
index 05cef82..94c83f2 100644
--- a/circle.yml
+++ b/circle.yml
@@ -1,14 +1,30 @@
+---
+machine:
+  pre:
+    # https://github.com/commercialhaskell/stack/issues/1658
+    - sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.6 20
+    - sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-4.6 20
+    - sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.9 10
+    - sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-4.9 10
 dependencies:
   cache_directories:
     - "~/.stack"
   pre:
-    - wget https://github.com/commercialhaskell/stack/releases/download/v1.4.0/stack-1.4.0-linux-x86_64.tar.gz -O /tmp/stack.tar.gz
-    - tar xvzOf /tmp/stack.tar.gz stack-1.4.0-linux-x86_64/stack > /tmp/stack
+    - wget https://github.com/commercialhaskell/stack/releases/download/v1.6.1/stack-1.6.1-linux-x86_64.tar.gz -O /tmp/stack.tar.gz
+    - tar xvzOf /tmp/stack.tar.gz stack-1.6.1-linux-x86_64/stack > /tmp/stack
     - chmod +x /tmp/stack && sudo mv /tmp/stack /usr/bin/stack
   override:
     - stack setup
-    - stack build --flag yesod-auth-oauth2:example
+    - stack build
+      --pedantic
+      --test --no-run-tests
+      --flag yesod-auth-oauth2:example
 
 test:
   override:
     - stack test
+
+    # Check compilation with nightly. If this proves problematic, add || true
+    # after to not fail the build.
+    - stack setup --resolver nightly
+    - stack build --resolver nightly --pedantic --test --no-run-tests
diff --git a/stack.yaml b/stack.yaml
index 6cecc95..1b47e39 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -1,8 +1,9 @@
-resolver: lts-9.5
+---
+resolver: lts-9.18
 flags:
   yesod-auth-oauth2:
     network-uri: true
 packages:
-- .
+  - .
 extra-deps:
-- load-env-0.1.1
+  - load-env-0.1.1
diff --git a/yesod-auth-oauth2.cabal b/yesod-auth-oauth2.cabal
index dd83976..93b97a8 100644
--- a/yesod-auth-oauth2.cabal
+++ b/yesod-auth-oauth2.cabal
@@ -31,7 +31,7 @@ library
                    , http-client             >= 0.4.0     && < 0.6
                    , http-conduit            >= 2.0       && < 3.0
                    , http-types              >= 0.8       && < 0.10
-                   , aeson                   >= 0.6       && < 1.2
+                   , aeson                   >= 0.6       && < 1.3
                    , yesod-core              >= 1.2       && < 1.5
                    , authenticate            >= 1.3.2.7   && < 1.4
                    , random
@@ -39,7 +39,7 @@ library
                    , text                    >= 0.7       && < 2.0
                    , yesod-form              >= 1.3       && < 1.5
                    , transformers            >= 0.2.2     && < 0.6
-                   , hoauth2                 >= 1.3.0     && < 1.4
+                   , hoauth2                 >= 1.3.0     && < 1.6
                    , lifted-base             >= 0.2       && < 0.4
                    , vector                  >= 0.10      && < 0.13
                    , uri-bytestring
@@ -89,6 +89,7 @@ test-suite test
                  , yesod-auth-oauth2
                  , hspec
                  , uri-bytestring
+  other-modules:   URI.ByteString.ExtensionSpec
 
 source-repository head
   type:     git