diff --git a/README.md b/README.md
index 5b55acd1c58d58f6e258605f82083099088bc9c6..bfb5996a29b1a12ad8b9e8b280ea84750805d951 100644
--- a/README.md
+++ b/README.md
@@ -51,7 +51,7 @@ HPC systems, see [here](#special-instructions-for-installation-on-jülich-hpc-sy
 
 * depending on the pre-installed packages it could be required to install further packages
 
-`sudo zypper install libproj-devel binutils gdal-devel graphviz`
+`sudo zypper install libproj-devel binutils gdal-devel graphviz graphviz-gnome`
 
 * python develop libraries
 
diff --git a/docs/_source/get-started.rst b/docs/_source/get-started.rst
index ede3cebfb7e1d9f673da3751c0cc2ab4dfba12ea..d51abaf4e1f256a420182c8d93055e99760b6963 100644
--- a/docs/_source/get-started.rst
+++ b/docs/_source/get-started.rst
@@ -55,7 +55,7 @@ openSUSE Leap 15.1
 
 * depending on the pre-installed packages it could be required to install further packages
 
-:py:`sudo zypper install libproj-devel binutils gdal-devel graphviz`
+:py:`sudo zypper install libproj-devel binutils gdal-devel graphviz graphviz-gnome`
 
 * python develop libraries
 
diff --git a/requirements.txt b/requirements.txt
index 47995404d7c8c202071197bb2aab9dba81e18689..af24bfc2ad000418daaee8e452ebe17bc24062fe 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -33,7 +33,7 @@ patsy==0.5.1
 Pillow==7.0.0
 pluggy==0.13.1
 protobuf==3.11.3
-py==1.8.1
+py==1.10.0
 pydot==1.4.1
 pyparsing==2.4.6
 pyproj==2.5.0