diff --git a/all-spark-notebook/README.md b/all-spark-notebook/README.md
index ff24fcae..72dd1960 100644
--- a/all-spark-notebook/README.md
+++ b/all-spark-notebook/README.md
@@ -4,7 +4,7 @@
 
 ## What it Gives You
 
-* Jupyter Notebook 4.1.x
+* Jupyter Notebook 4.2.x
 * Conda Python 3.x and Python 2.7.x environments
 * Conda R 3.2.x environment
 * Scala 2.10.x
diff --git a/datascience-notebook/README.md b/datascience-notebook/README.md
index 717e5735..09a5c741 100644
--- a/datascience-notebook/README.md
+++ b/datascience-notebook/README.md
@@ -4,7 +4,7 @@
 
 ## What it Gives You
 
-* Jupyter Notebook 4.1.x
+* Jupyter Notebook 4.2.x
 * Conda Python 3.x and Python 2.7.x environments
 * pandas, matplotlib, scipy, seaborn, scikit-learn, scikit-image, sympy, cython, patsy, statsmodel, cloudpickle, dill, numba, bokeh pre-installed
 * Conda R v3.2.x and channel
diff --git a/minimal-notebook/Dockerfile b/minimal-notebook/Dockerfile
index b36144d8..a264c6f1 100644
--- a/minimal-notebook/Dockerfile
+++ b/minimal-notebook/Dockerfile
@@ -79,7 +79,7 @@ RUN cd /tmp && \
 
 # Install Jupyter notebook as jovyan
 RUN conda install --quiet --yes \
-    'notebook=4.1*' \
+    'notebook=4.2*' \
     terminado \
     && conda clean -tipsy
 
diff --git a/minimal-notebook/README.md b/minimal-notebook/README.md
index bf350228..1fbf7140 100644
--- a/minimal-notebook/README.md
+++ b/minimal-notebook/README.md
@@ -4,7 +4,7 @@
 
 ## What it Gives You
 
-* Jupyter Notebook 4.1.x
+* Jupyter Notebook 4.2.x
 * Conda Python 3.x
 * No preinstalled scientific computing packages
 * Unprivileged user `jovyan` (uid=1000, configurable, see options) in group `users` (gid=100) with ownership over `/home/jovyan` and `/opt/conda`
diff --git a/pyspark-notebook/Dockerfile b/pyspark-notebook/Dockerfile
index 52146f49..d33179f0 100644
--- a/pyspark-notebook/Dockerfile
+++ b/pyspark-notebook/Dockerfile
@@ -46,7 +46,7 @@ USER jovyan
 
 # Install Python 3 packages
 RUN conda install --quiet --yes \
-    'ipywidgets=4.1*' \
+    'ipywidgets=5.1*' \
     'pandas=0.17*' \
     'numexpr=2.5*' \
     'matplotlib=1.5*' \
@@ -54,11 +54,13 @@ RUN conda install --quiet --yes \
     'seaborn=0.7*' \
     'scikit-learn=0.17*' \
     && conda clean -tipsy
-
+# Activate ipywidgets extension in the environment that runs the notebook server
+RUN jupyter nbextension enable --py widgetsnbextension --sys-prefix
+    
 # Install Python 2 packages and kernel spec
 RUN conda create --quiet --yes -p $CONDA_DIR/envs/python2 python=2.7 \
-    'ipython=4.1*' \
-    'ipywidgets=4.1*' \
+    'ipython=4.2*' \
+    'ipywidgets=5.1*' \
     'pandas=0.17*' \
     'numexpr=2.5*' \
     'matplotlib=1.5*' \
diff --git a/pyspark-notebook/README.md b/pyspark-notebook/README.md
index 6e2fb18e..a22e1b09 100644
--- a/pyspark-notebook/README.md
+++ b/pyspark-notebook/README.md
@@ -4,7 +4,7 @@
 
 ## What it Gives You
 
-* Jupyter Notebook 4.1.x
+* Jupyter Notebook 4.2.x
 * Conda Python 3.x and Python 2.7.x environments
 * pyspark, pandas, matplotlib, scipy, seaborn, scikit-learn pre-installed
 * Spark 1.6.0 for use in local mode or to connect to a cluster of Spark workers
diff --git a/r-notebook/README.md b/r-notebook/README.md
index 2726f811..8d4db490 100644
--- a/r-notebook/README.md
+++ b/r-notebook/README.md
@@ -4,7 +4,7 @@
 
 ## What it Gives You
 
-* Jupyter Notebook 4.1.x
+* Jupyter Notebook 4.2.x
 * Conda R v3.2.x and channel
 * plyr, devtools, dplyr, ggplot2, tidyr, shiny, rmarkdown, forecast, stringr, rsqlite, reshape2, nycflights13, caret, rcurl, and randomforest pre-installed
 * Unprivileged user `jovyan` (uid=1000, configurable, see options) in group `users` (gid=100) with ownership over `/home/jovyan` and `/opt/conda`
diff --git a/scipy-notebook/Dockerfile b/scipy-notebook/Dockerfile
index 12b1c3c8..f1434029 100644
--- a/scipy-notebook/Dockerfile
+++ b/scipy-notebook/Dockerfile
@@ -16,7 +16,7 @@ USER jovyan
 
 # Install Python 3 packages
 RUN conda install --quiet --yes \
-    'ipywidgets=4.1*' \
+    'ipywidgets=5.1*' \
     'pandas=0.17*' \
     'numexpr=2.5*' \
     'matplotlib=1.5*' \
@@ -34,11 +34,13 @@ RUN conda install --quiet --yes \
     'bokeh=0.11*' \
     'h5py=2.5*' \
     && conda clean -tipsy
+# Activate ipywidgets extension in the environment that runs the notebook server
+RUN jupyter nbextension enable --py widgetsnbextension --sys-prefix
 
 # Install Python 2 packages
 RUN conda create --quiet --yes -p $CONDA_DIR/envs/python2 python=2.7 \
-    'ipython=4.1*' \
-    'ipywidgets=4.1*' \
+    'ipython=4.2*' \
+    'ipywidgets=5.1*' \
     'pandas=0.17*' \
     'numexpr=2.5*' \
     'matplotlib=1.5*' \
diff --git a/scipy-notebook/README.md b/scipy-notebook/README.md
index ad30b5ae..2d3b027d 100644
--- a/scipy-notebook/README.md
+++ b/scipy-notebook/README.md
@@ -4,7 +4,7 @@
 
 ## What it Gives You
 
-* Jupyter Notebook 4.1.x
+* Jupyter Notebook 4.2.x
 * Conda Python 3.x and Python 2.7.x environments
 * pandas, matplotlib, scipy, seaborn, scikit-learn, scikit-image, sympy, cython, patsy, statsmodel, cloudpickle, dill, numba, bokeh pre-installed
 * Unprivileged user `jovyan` (uid=1000, configurable, see options) in group `users` (gid=100) with ownership over `/home/jovyan` and `/opt/conda`