diff --git a/base-notebook/Dockerfile b/base-notebook/Dockerfile
index f2e147ab36..c8d3651b79 100644
--- a/base-notebook/Dockerfile
+++ b/base-notebook/Dockerfile
@@ -131,8 +131,8 @@ RUN wget --quiet "https://github.com/conda-forge/miniforge/releases/download/${m
 # Do all this in a single RUN command to avoid duplicating all of the
 # files across image layers when the permissions change
 RUN conda install --quiet --yes \
-    'notebook=6.1.5' \
-    'jupyterhub=1.2.2' \
+    'notebook=6.1.6' \
+    'jupyterhub=1.3.0' \
     'jupyterlab=2.2.9' && \
     conda clean --all -f -y && \
     npm cache clean --force && \
@@ -150,10 +150,16 @@ CMD ["start-notebook.sh"]
 
 # Copy local files as late as possible to avoid cache busting
 COPY start.sh start-notebook.sh start-singleuser.sh /usr/local/bin/
+# Currently need to have both jupyter_notebook_config and jupyter_server_config to support classic and lab
 COPY jupyter_notebook_config.py /etc/jupyter/
 
 # Fix permissions on /etc/jupyter as root
 USER root
+
+# Prepare upgrade to JupyterLab V3.0 #1205
+RUN sed -re "s/c.NotebookApp/c.ServerApp/g" \
+    /etc/jupyter/jupyter_notebook_config.py > /etc/jupyter/jupyter_server_config.py
+
 RUN fix-permissions /etc/jupyter/
 
 # Switch back to jovyan to avoid accidental container runs as root
diff --git a/datascience-notebook/Dockerfile b/datascience-notebook/Dockerfile
index 3296bbee9c..7965381aa9 100644
--- a/datascience-notebook/Dockerfile
+++ b/datascience-notebook/Dockerfile
@@ -70,7 +70,7 @@ RUN conda install --quiet --yes \
     'r-nycflights13=1.0*' \
     'r-randomforest=4.6*' \
     'r-rcurl=1.98*' \
-    'r-rmarkdown=2.5*' \
+    'r-rmarkdown=2.6*' \
     'r-rsqlite=2.2*' \
     'r-shiny=1.5*' \
     'r-tidyverse=1.3*' \
diff --git a/r-notebook/Dockerfile b/r-notebook/Dockerfile
index d316de97ce..190de532cb 100644
--- a/r-notebook/Dockerfile
+++ b/r-notebook/Dockerfile
@@ -37,7 +37,7 @@ RUN conda install --quiet --yes \
     'r-nycflights13=1.0*' \
     'r-randomforest=4.6*' \
     'r-rcurl=1.98*' \
-    'r-rmarkdown=2.5*' \
+    'r-rmarkdown=2.6*' \
     'r-rodbc=1.3*' \
     'r-rsqlite=2.2*' \
     'r-shiny=1.5*' \
diff --git a/scipy-notebook/Dockerfile b/scipy-notebook/Dockerfile
index 2a634b1a0c..627553d2d1 100644
--- a/scipy-notebook/Dockerfile
+++ b/scipy-notebook/Dockerfile
@@ -22,20 +22,20 @@ RUN conda install --quiet --yes \
     'bottleneck=1.3.*' \
     'cloudpickle=1.6.*' \
     'cython=0.29.*' \
-    'dask=2.30.*' \
+    'dask=2020.12.*' \
     'dill=0.3.*' \
     'h5py=3.1.*' \
-    'ipywidgets=7.5.*' \
+    'ipywidgets=7.6.*' \
     'ipympl=0.5.*'\
     'matplotlib-base=3.3.*' \
-    'numba=0.51.*' \
+    'numba=0.52.*' \
     'numexpr=2.7.*' \
     'pandas=1.1.*' \
     'patsy=0.5.*' \
-    'protobuf=3.13.*' \
+    'protobuf=3.14.*' \
     'pytables=3.6.*' \
-    'scikit-image=0.17.*' \
-    'scikit-learn=0.23.*' \
+    'scikit-image=0.18.*' \
+    'scikit-learn=0.24.*' \
     'scipy=1.5.*' \
     'seaborn=0.11.*' \
     'sqlalchemy=1.3.*' \
diff --git a/scipy-notebook/test/test_extensions.py b/scipy-notebook/test/test_extensions.py
new file mode 100644
index 0000000000..f1e1e97383
--- /dev/null
+++ b/scipy-notebook/test/test_extensions.py
@@ -0,0 +1,27 @@
+# Copyright (c) Jupyter Development Team.
+# Distributed under the terms of the Modified BSD License.
+import logging
+
+import pytest
+
+LOGGER = logging.getLogger(__name__)
+
+
+@pytest.mark.parametrize(
+    "extension",
+    [
+        "@bokeh/jupyter_bokeh",
+        "@jupyter-widgets/jupyterlab-manager",
+        "jupyter-matplotlib",
+    ],
+)
+def test_check_extension(container, extension):
+    """Basic check of each extension"""
+    LOGGER.info(f"Checking the extension: {extension} ...")
+    c = container.run(
+        tty=True, command=["start.sh", "jupyter", "labextension", "check", extension]
+    )
+    rv = c.wait(timeout=10)
+    logs = c.logs(stdout=True).decode("utf-8")
+    LOGGER.debug(logs)
+    assert rv == 0 or rv["StatusCode"] == 0, f"Extension {extension} check failed"
diff --git a/tensorflow-notebook/Dockerfile b/tensorflow-notebook/Dockerfile
index 1ad8ce1405..ce20cf84b7 100644
--- a/tensorflow-notebook/Dockerfile
+++ b/tensorflow-notebook/Dockerfile
@@ -7,6 +7,6 @@ LABEL maintainer="Jupyter Project <jupyter@googlegroups.com>"
 
 # Install Tensorflow
 RUN pip install --quiet --no-cache-dir \
-    'tensorflow==2.3.1' && \
+    'tensorflow==2.4.0' && \
     fix-permissions "${CONDA_DIR}" && \
     fix-permissions "/home/${NB_USER}"