diff --git a/.circleci/config.yml b/.circleci/config.yml
index 3d41ae6..25d2f30 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -35,7 +35,7 @@ commands:
           command: ./scripts/build-librdkafka
       - save_cache:
           key: cache--{{ .Environment.CACHE_VERSION }}--librdkafka--{{ checksum "scripts/build-librdkafka" }}
-          paths: .librdkafka
+          paths: [ .librdkafka ]
 
 workflows:
   build-app-pipelines:
diff --git a/hw-kafka-client.cabal b/hw-kafka-client.cabal
index c637b95..9cf57cf 100644
--- a/hw-kafka-client.cabal
+++ b/hw-kafka-client.cabal
@@ -1,7 +1,7 @@
 cabal-version: 2.2
 
 name:                   hw-kafka-client
-version:                3.1.2
+version:                4.0.0
 synopsis:               Kafka bindings for Haskell
 description:            Apache Kafka bindings backed by the librdkafka C library.
                         .