diff --git a/README.md b/README.md
index 9d53db5..5e4f170 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # krangl
 
-[ ![Download](https://img.shields.io/badge/Maven%20Central-0.18.3-orange) ](https://mvnrepository.com/artifact/com.github.holgerbrandl/krangl)  [![Build Status](https://github.com/holgerbrandl/krangl/workflows/build/badge.svg)](https://github.com/holgerbrandl/krangl/actions?query=workflow%3Abuild) [![Gitter](https://badges.gitter.im/holgerbrandl/krangl.svg)](https://gitter.im/holgerbrandl/krangl?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge)
+[ ![Download](https://img.shields.io/badge/Maven%20Central-0.18.4-orange) ](https://mvnrepository.com/artifact/com.github.holgerbrandl/krangl)  [![Build Status](https://github.com/holgerbrandl/krangl/workflows/build/badge.svg)](https://github.com/holgerbrandl/krangl/actions?query=workflow%3Abuild) [![Gitter](https://badges.gitter.im/holgerbrandl/krangl.svg)](https://gitter.im/holgerbrandl/krangl?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge)
 
 `krangl` is a {K}otlin library for data w{rangl}ing. By implementing a grammar of data manipulation using a modern functional-style API, it allows to filter, transform, aggregate and reshape tabular data.
 
@@ -32,7 +32,7 @@ repositories {
 }
 
 dependencies {
-    implementation "com.github.holgerbrandl:krangl:0.18.3"
+    implementation "com.github.holgerbrandl:krangl:0.18.4"
 }
 ```
 Declaring the repository is purely optional as it is the default already.
diff --git a/build.gradle b/build.gradle
index 2ad9410..1173841 100644
--- a/build.gradle
+++ b/build.gradle
@@ -30,7 +30,8 @@ dependencies {
 
     api 'org.apache.commons:commons-csv:1.6' // cant upgrade to 1.8 because of https://issues.apache.org/jira/browse/CSV-257
 
-//    api 'org.apache.arrow:arrow-vector:8.0.0'
+    compileOnly 'org.apache.arrow:arrow-vector:8.0.0'
+    testImplementation 'org.apache.arrow:arrow-vector:8.0.0'
     compileOnly 'org.apache.arrow:arrow-memory-netty:8.0.0'
     testImplementation 'org.apache.arrow:arrow-memory-netty:8.0.0'
 
@@ -109,7 +110,7 @@ test {
 //http://stackoverflow.com/questions/34377367/why-is-gradle-install-replacing-my-version-with-unspecified
 group 'com.github.holgerbrandl'
 //version '0.16.95'
-version '0.18.3'
+version '0.18.4'
 
 processJupyterApiResources {
     libraryProducers = ["krangl.integration.Integration"]
diff --git a/docs/userguide/docs/index.md b/docs/userguide/docs/index.md
index 4b1ac5e..81a0a95 100644
--- a/docs/userguide/docs/index.md
+++ b/docs/userguide/docs/index.md
@@ -1,4 +1,4 @@
-[ ![Download](https://img.shields.io/badge/Maven%20Central-0.18.3-orange) ](https://mvnrepository.com/artifact/com.github.holgerbrandl.krangl/krangl)  [![Build Status](https://github.com/holgerbrandl/krangl/workflows/build/badge.svg)](https://github.com/holgerbrandl/krangl/actions?query=workflow%3Abuild) [![Gitter](https://badges.gitter.im/holgerbrandl/krangl.svg)](https://gitter.im/holgerbrandl/krangl?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge)
+[ ![Download](https://img.shields.io/badge/Maven%20Central-0.18.4-orange) ](https://mvnrepository.com/artifact/com.github.holgerbrandl.krangl/krangl)  [![Build Status](https://github.com/holgerbrandl/krangl/workflows/build/badge.svg)](https://github.com/holgerbrandl/krangl/actions?query=workflow%3Abuild) [![Gitter](https://badges.gitter.im/holgerbrandl/krangl.svg)](https://gitter.im/holgerbrandl/krangl?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge)
 
 This is the manual of [krangl](https://github.com/holgerbrandl/krangl).
 
@@ -40,7 +40,7 @@ repositories {
 }
 
 dependencies {
-    implementation "com.github.holgerbrandl:krangl:0.18.3"
+    implementation "com.github.holgerbrandl:krangl:0.18.4"
 }
 ```
 Declaring the repository is purely optional as it is the default already.