diff --git a/handson-ml-master/requirements.txt b/handson-ml-master/requirements.txt
index 7df1ca3..df58ac8 100644
--- a/handson-ml-master/requirements.txt
+++ b/handson-ml-master/requirements.txt
@@ -25,7 +25,7 @@ numexpr==2.6.3
 numpy==1.13.1
 pandas==0.20.3
 Pillow==4.2.1
-protobuf==3.4.0
+protobuf==6.33.5
 psutil==5.3.1
 scikit-learn==0.19.0
 scipy==0.19.1
@@ -42,3 +42,4 @@ tensorflow==1.3.0
 # Optional: these are useful Jupyter extensions, in particular to display
 # the table of contents.
 https://github.com/ipython-contrib/jupyter_contrib_nbextensions/tarball/master
+nbconvert>=7.17.0 # not directly required, pinned by Snyk to avoid a vulnerability