diff --git a/charts/flagger/Chart.yaml b/charts/flagger/Chart.yaml
index eb6ac91a8..77788dd95 100644
--- a/charts/flagger/Chart.yaml
+++ b/charts/flagger/Chart.yaml
@@ -1,8 +1,8 @@
 apiVersion: v1
 name: flagger
-version: 0.3.0
+version: 0.4.0
 appVersion: 0.3.1-alpha.1
-kubeVersion: ">=1.9.0-0"
+kubeVersion: ">=1.11.0-0"
 engine: gotpl
 description: Flagger is a Kubernetes operator that automates the promotion of canary deployments using Istio routing for traffic shifting and Prometheus metrics for canary analysis.
 home: https://docs.flagger.app
diff --git a/charts/flagger/README.md b/charts/flagger/README.md
index 96fd2d922..2a541a4b1 100644
--- a/charts/flagger/README.md
+++ b/charts/flagger/README.md
@@ -8,7 +8,7 @@ Based on the KPIs analysis a canary is promoted or aborted and the analysis resu
 
 ## Prerequisites
 
-* Kubernetes >= 1.9
+* Kubernetes >= 1.11
 * Istio >= 1.0
 * Prometheus >= 2.6
 
diff --git a/docs/gitbook/README.md b/docs/gitbook/README.md
index 448281486..92dba1e32 100644
--- a/docs/gitbook/README.md
+++ b/docs/gitbook/README.md
@@ -4,13 +4,20 @@ description: Flagger is an Istio progressive delivery Kubernetes operator
 
 # Introduction
 
-[Flagger](https://github.com/stefanprodan/flagger) is a **Kubernetes** operator that automates the promotion of canary deployments using **Istio** routing for traffic shifting and **Prometheus** metrics for canary analysis.
+[Flagger](https://github.com/stefanprodan/flagger) is a **Kubernetes** operator that automates the promotion of canary 
+deployments using **Istio** routing for traffic shifting and **Prometheus** metrics for canary analysis.
+The canary analysis can be extended with webhooks for running integration tests, 
+load tests or any other custom validation.
 
-Flagger implements a control loop that gradually shifts traffic to the canary while measuring key performance indicators like HTTP requests success rate, requests average duration and pods health. Based on the **KPIs** analysis a canary is promoted or aborted and the analysis result is published to **Slack**.
+Flagger implements a control loop that gradually shifts traffic to the canary while measuring key performance 
+indicators like HTTP requests success rate, requests average duration and pods health. 
+Based on the **KPIs** analysis a canary is promoted or aborted and the analysis result is published to **Slack**.
 
 ![Flagger overview diagram](https://github.com/raw/stefanprodan/flagger/master/docs/diagrams/flagger-canary-overview.png)
 
-Flagger can be configured with Kubernetes custom resources \(canaries.flagger.app kind\) and is compatible with any CI/CD solutions made for Kubernetes. Since Flagger is declarative and reacts to Kubernetes events, it can be used in **GitOps** pipelines together with Weave Flux or JenkinsX.
+Flagger can be configured with Kubernetes custom resources \(canaries.flagger.app kind\) and is compatible with 
+any CI/CD solutions made for Kubernetes. Since Flagger is declarative and reacts to Kubernetes events, 
+it can be used in **GitOps** pipelines together with Weave Flux or JenkinsX.
 
 This project is sponsored by [Weaveworks](https://www.weave.works/)
 
diff --git a/docs/gitbook/install/install-flagger.md b/docs/gitbook/install/install-flagger.md
index 2b8c4d76a..fd85d34de 100644
--- a/docs/gitbook/install/install-flagger.md
+++ b/docs/gitbook/install/install-flagger.md
@@ -6,7 +6,7 @@ If you are new to Istio you can follow this GKE guide
 
 **Prerequisites**
 
-* Kubernetes >= 1.9
+* Kubernetes >= 1.11
 * Istio >= 1.0
 * Prometheus >= 2.6