diff --git a/gpu.Dockerfile b/gpu.Dockerfile
index cd8051c3..63b429ba 100644
--- a/gpu.Dockerfile
+++ b/gpu.Dockerfile
@@ -63,5 +63,17 @@ RUN pip install pycuda && \
     pip install pynvrtc && \
     /tmp/clean-layer.sh
 
+# Install NVIDA Apex
+# Make sure we don't overwrite some existing directory called "apex"
+WORKDIR /tmp/unique_for_apex
+# uninstall Apex if present, twice to make absolutely sure :)
+RUN pip uninstall -y apex || :
+RUN pip uninstall -y apex || :
+# SHA is something the user can touch to force recreation of this Docker layer,
+# and therefore force cloning of the latest version of Apex
+RUN SHA=ToUcHMe git clone https://github.com/NVIDIA/apex.git
+WORKDIR /tmp/unique_for_apex/apex
+RUN pip install -v --no-cache-dir --global-option="--cpp_ext" --global-option="--cuda_ext" .
+
 # Re-add TensorBoard Jupyter extension patch
 ADD patches/tensorboard/notebook.py /opt/conda/lib/python3.6/site-packages/tensorboard/notebook.py