diff --git a/R/highcharter-helper.R b/R/highcharter-helper.R
index ad2168c..6601655 100644
--- a/R/highcharter-helper.R
+++ b/R/highcharter-helper.R
@@ -136,3 +136,11 @@
   }
   hc
 }
+
+.onAttach <- function(libname = find.package("RKorAPClient"),
+                      pkgname = "RKorAPClient") {
+  packageStartupMessage(
+    "If you intend to use the Highcharts plot options, please note that Highcharts (www.highcharts.com) is a Highsoft software product which is not free for commercial and governmental use."
+  )
+}
+
diff --git a/Readme.md b/Readme.md
index 46b8969..06985a3 100644
--- a/Readme.md
+++ b/Readme.md
@@ -54,6 +54,7 @@
 ![](man/figures/Readme-Example-1.png)<!-- -->
 
 ### Percentages over time using [highcharter](http://jkunst.com/highcharter/)
+See the [Highcharts license notes](#highcharts) below.
 ```r
 library(RKorAPClient)
 query = c("macht []{0,3} Sinn", "ergibt []{0,3} Sinn")
@@ -83,6 +84,13 @@
 It is published under the
 [BSD-2 License](LICENSE.md).
 
+### Used Packages and Libraries
+
+#### Highcharts
+RKorAPClient imports parts of the [highcharter package](https://cran.r-project.org/package=highcharter) which has a dependency on Highcharts, a commercial JavaScript charting library. Highcharts offers both a commercial license as well as a free non-commercial license. Please review the licensing options and terms before using the highcharter plot options, as the `RKorAPClient` license neither provides nor implies a license for Highcharts.
+
+[Highcharts](http://highcharts.com) is a Highsoft product which is not free for commercial and governmental use.
+
 ## Contributions
 
 Contributions are very welcome!