diff --git a/Pipfile b/Pipfile
index b77dce7..ad66809 100644
--- a/Pipfile
+++ b/Pipfile
@@ -5,6 +5,7 @@ name = "pypi"
 
 [packages]
 runner = {editable = true, path = "."}
+graphviz = "*"
 
 [dev-packages]
 sphinx = "*"
diff --git a/docs/requirements.txt b/docs/requirements.txt
index eca5d27..8602a16 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,6 +1,6 @@
-numpy==1.18.5
-numpydoc==1.0.0
-ase==3.19.0
-psutil==5.7.3
-docutils==0.16
-graphviz==0.14.1
+numpy
+numpydoc
+ase
+psutil
+docutils
+graphviz