diff --git a/ci/docker_images/ubuntu/bionic/Dockerfile b/ci/docker_images/ubuntu/bionic/Dockerfile
index c51c43bb5eb3419d5bc7cdbbb764e43bdfc9fafe..dcd4f1cd110ce34a79048d31e69c72465265eacb 100644
--- a/ci/docker_images/ubuntu/bionic/Dockerfile
+++ b/ci/docker_images/ubuntu/bionic/Dockerfile
@@ -48,10 +48,10 @@ RUN apt-get install -y libcairomm-1.0-dev
 RUN apt-get install -y python
 RUN apt-get install -y python-dev
 RUN apt-get install -y python-pip
+RUN apt-get install -y python-tk
 RUN apt-get install -y opencl-headers
 RUN apt-get install -y ocl-icd-libopencl1
 RUN apt-get install -y clinfo
-RUN apt-get install -y python-tk
 
 # python packages
 RUN pip install --upgrade pip
@@ -127,6 +127,7 @@ RUN ldconfig
 
 # pyopencl
 RUN cd /tmp                                       \
+&& pip install pybind11                           \
 && git clone https://github.com/inducer/pyopencl  \
 && cd pyopencl                                    \
 && git submodule update --init                    \
diff --git a/ci/docker_images/ubuntu/bionic_cuda/Dockerfile b/ci/docker_images/ubuntu/bionic_cuda/Dockerfile
index e7d149c2d7997012043de004345f460ded2c3b88..ed8e82c8dcdefa3d1b71685b14ab9b09251fb9ac 100644
--- a/ci/docker_images/ubuntu/bionic_cuda/Dockerfile
+++ b/ci/docker_images/ubuntu/bionic_cuda/Dockerfile
@@ -127,6 +127,7 @@ RUN ldconfig
 
 # pyopencl
 RUN cd /tmp                                       \
+&& pip install pybind11                           \
 && git clone https://github.com/inducer/pyopencl  \
 && cd pyopencl                                    \
 && git submodule update --init                    \