diff --git a/Dockerfile b/Dockerfile
index 604b2ea1..88d1ea7b 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -35,141 +35,31 @@ ARG EXAFMM_VERSION
 
 WORKDIR /tmp
 
-# Install dependencies available via apt-get.
-# - First set of packages are required to build and run Bempp-cl.
-# - Second set of packages are recommended and/or required to build
-#   documentation or tests.
-# - Third set of packages are optional, but required to run gmsh
-#   pre-built binaries.
-# - Fourth set of packages are optional, required for meshio.
 RUN export DEBIAN_FRONTEND=noninteractive && \
     apt-get -qq update && \
     apt-get -yq --with-new-pkgs -o Dpkg::Options::="--force-confold" upgrade && \
     apt-get -y install \
-    cmake \
-    git \
-    ipython3 \
-    pkg-config \
-    python-is-python3 \
-    python3-dev \
-    python3-matplotlib \
-    python3-mpi4py \
-    python3-pip \
-    python3-pyopencl \
-    python3-scipy \
-    python3-setuptools \
-    jupyter \
-    wget && \
-    apt-get -y install \
-    libfftw3-dev \
-    libfltk-gl1.3 \
-    libfltk-images1.3 \
-    libfltk1.3 \
-    libfreeimage3 \
-    libgl2ps1.4 \
-    libglu1-mesa \
-    libilmbase25 \
-    libjxr0 \
-    libocct-data-exchange-7.5 \
-    libocct-foundation-7.5 \
-    libocct-modeling-algorithms-7.5 \
-    libocct-modeling-data-7.5 \ 
-    libocct-ocaf-7.5 \
-    libocct-visualization-7.5 \
-    libopenblas-dev \
-    libopenexr25 \
-    libopenjp2-7 \
-    libraw-dev \
-    libtbb2 \
-    libxcursor1 \
-    libxinerama1 && \
-    apt-get -y install \
-    python3-lxml && \
-    apt-get clean && \
-    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
-
-# Install Python packages (via pip)
-RUN pip3 install --no-cache-dir "numpy>=1.21,<1.23" numba>=0.55.2 meshio>=4.0.16 && \
-    pip3 install --no-cache-dir flake8 pytest pydocstyle pytest-xdist
-
-# Download Install Gmsh SDK
-RUN cd /usr/local && \
-    wget -nc --quiet http://gmsh.info/bin/Linux/gmsh-${GMSH_VERSION}-Linux64-sdk.tgz && \
-    tar -xf gmsh-${GMSH_VERSION}-Linux64-sdk.tgz && \
-    rm gmsh-${GMSH_VERSION}-Linux64-sdk.tgz
-
-ENV PATH=/usr/local/gmsh-${GMSH_VERSION}-Linux64-sdk/bin:$PATH
-
-RUN git clone -b v${EXAFMM_VERSION} https://github.com/exafmm/exafmm-t.git
-RUN cd exafmm-t && sed -i 's/march=native/march=ivybridge/g' ./setup.py && python3 setup.py install
-
-# Clear /tmp
-RUN rm -rf /tmp/*
-
-WORKDIR /root
-
-########################################
-
-FROM ubuntu:22.04 as bempp-dev-env-with-dolfin
-LABEL maintainer="Matthew Scroggs <bempp@mscroggs.co.uk>"
-LABEL description="Bempp-cl development environment with FEniCS"
-
-ARG GMSH_VERSION
-ARG MAKEFLAGS
-ARG EXAFMM_VERSION
-
-WORKDIR /tmp
-
-# Install dependencies
-RUN export DEBIAN_FRONTEND=noninteractive && \
-    apt-get -qq update && \
-    apt-get -yq --with-new-pkgs -o Dpkg::Options::="--force-confold" upgrade && \
-    apt-get -y install \
-    cmake \
-    git \
-    ipython3 \
-    pkg-config \
-    python-is-python3 \
-    python3-dev \
-    python3-mpi4py \
-    python3-pip \
-    python3-pyopencl \
-    python3-setuptools \
-    jupyter \
-    wget && \
-    apt-get -y install \
-    libfftw3-dev \
-    libfltk-gl1.3 \
-    libfltk-images1.3 \
-    libfltk1.3 \
-    libfreeimage3 \
-    libgl2ps1.4 \
-    libglu1-mesa \
-    libilmbase25 \
-    libjxr0 \
-    libocct-data-exchange-7.5 \
-    libocct-foundation-7.5 \
-    libocct-modeling-algorithms-7.5 \
-    libocct-modeling-data-7.5 \ 
-    libocct-ocaf-7.5 \
-    libocct-visualization-7.5 \
-    libopenblas-dev \
-    libopenexr25 \
-    libopenjp2-7 \
-    libraw-dev \
-    libtbb2 \
-    libxcursor1 \
-    libxinerama1
-RUN pip3 install --no-cache-dir meshio>=4.0.16 \
-    numba numpy==1.20 scipy matplotlib && \
-    pip3 install --no-cache-dir flake8 pytest pydocstyle pytest-xdist
-RUN apt-get -y install \
-    python3-dolfin \
-    python3-lxml && \
-    apt-get clean && \
-    rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
-
-# Install Python packages (via pip)
+        wget \
+        git \
+        pkg-config \
+        build-essential \
+        # ExaFMM dependencies
+        libfftw3-dev \
+        libopenblas-dev \
+        # Gmsh dependencies
+        libfltk-gl1.3 \
+        libfltk-images1.3 \
+        libfltk1.3 \
+        libglu1-mesa \
+        # OpenCL
+        libpocl-dev \
+        # Python
+        python3-dev \
+        python3-pip \
+    && apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
+
+RUN python3 -m pip install --no-cache-dir matplotlib pyopencl numpy scipy numba meshio && \
+    python3 -m pip install --no-cache-dir flake8 pytest pydocstyle pytest-xdist
 
 # Download Install Gmsh SDK
 RUN cd /usr/local && \
@@ -180,7 +70,7 @@ RUN cd /usr/local && \
 ENV PATH=/usr/local/gmsh-${GMSH_VERSION}-Linux64-sdk/bin:$PATH
 
 RUN git clone -b v${EXAFMM_VERSION} https://github.com/exafmm/exafmm-t.git
-RUN cd exafmm-t && sed -i 's/march=native/march=ivybridge/g' ./setup.py && python3 setup.py install
+RUN cd exafmm-t && sed -i 's/march=native/march=ivybridge/g' ./setup.py && python3 -m pip install .
 
 # Clear /tmp
 RUN rm -rf /tmp/*
@@ -207,19 +97,19 @@ RUN export DEBIAN_FRONTEND=noninteractive && \
     apt-get -qq update && \
     apt-get -yq --with-new-pkgs -o Dpkg::Options::="--force-confold" upgrade && \
     apt-get -y install \
-    libpugixml-dev \
-    python3-pyopencl \
-    python3-pybind11 \
-    libfftw3-dev \
-    pkg-config \
-    python-is-python3 \
+        # OpenCL
+        libpocl-dev \
+        # ExaFMM dependencies
+        libfftw3-dev \
     && \
     apt-get clean && \
     rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
 
+RUN python3 -m pip install --no-cache-dir matplotlib pyopencl numpy scipy numba meshio && \
+    python3 -m pip install --no-cache-dir flake8 pytest pydocstyle pytest-xdist
+
 # Install Python packages (via pip)
-RUN pip3 install --no-cache-dir meshio>=4.0.16 numpy matplotlib && \
-    pip3 install --upgrade six
+RUN python3 -m pip install --no-cache-dir meshio numpy matplotlib pyopencl
 
 # Install Basix
 RUN git clone --depth 1 --branch ${FENICSX_BASIX_TAG} https://github.com/FEniCS/basix.git basix-src && \
@@ -227,12 +117,12 @@ RUN git clone --depth 1 --branch ${FENICSX_BASIX_TAG} https://github.com/FEniCS/
     cmake -G Ninja -DCMAKE_BUILD_TYPE=Release -B build-dir -S . && \
     cmake --build build-dir && \
     cmake --install build-dir && \
-    pip3 install ./python
+    python3 -m pip install ./python
 
 # Install FEniCSx components
-RUN pip3 install --no-cache-dir ipython && \
-    pip3 install --no-cache-dir git+https://github.com/FEniCS/ufl.git@${FENICSX_UFL_TAG} && \
-    pip3 install --no-cache-dir git+https://github.com/FEniCS/ffcx.git@${FENICSX_FFCX_TAG}
+RUN python3 -m pip install --no-cache-dir ipython && \
+    python3 -m pip install --no-cache-dir git+https://github.com/FEniCS/ufl.git@${FENICSX_UFL_TAG} && \
+    python3 -m pip install --no-cache-dir git+https://github.com/FEniCS/ffcx.git@${FENICSX_FFCX_TAG}
 
 # Install FEniCSx
 RUN git clone --depth 1 --branch ${FENICSX_DOLFINX_TAG} https://github.com/fenics/dolfinx.git && \
@@ -243,7 +133,7 @@ RUN git clone --depth 1 --branch ${FENICSX_DOLFINX_TAG} https://github.com/fenic
     ninja ${DOLFINX_MAKEFLAGS} install && \
     . /usr/local/dolfinx-complex/lib/dolfinx/dolfinx.conf && \
     cd ../python && \
-    PETSC_ARCH=linux-gnu-complex-32 pip3 install --target /usr/local/dolfinx-complex/lib/python3.8/dist-packages --no-dependencies --ignore-installed .
+    PETSC_ARCH=linux-gnu-complex-32 python3 -m pip install --target /usr/local/dolfinx-complex/lib/python3.8/dist-packages --no-dependencies --ignore-installed .
 
 # complex by default.
 ENV LD_LIBRARY_PATH=/usr/local/dolfinx-complex/lib:$LD_LIBRARY_PATH \
@@ -256,7 +146,7 @@ ENV LD_LIBRARY_PATH=/usr/local/dolfinx-complex/lib:$LD_LIBRARY_PATH \
 RUN wget -nc --quiet https://github.com/exafmm/exafmm-t/archive/v${EXAFMM_VERSION}.tar.gz && \
     tar -xf v${EXAFMM_VERSION}.tar.gz && \
     cd exafmm-t-${EXAFMM_VERSION} && \
-    sed -i 's/march=native/march=ivybridge/g' ./setup.py && python3 setup.py install
+    sed -i 's/march=native/march=ivybridge/g' ./setup.py && python3 -m pip install .
 
 # Clear /tmp
 RUN rm -rf /tmp/*
@@ -283,18 +173,14 @@ RUN export DEBIAN_FRONTEND=noninteractive && \
     apt-get -qq update && \
     apt-get -yq --with-new-pkgs -o Dpkg::Options::="--force-confold" upgrade && \
     apt-get -y install \
-    python3-pybind11 \
-    python3-matplotlib \
+    # ExaFMM dependencies
     libfftw3-dev \
-    pkg-config \
-    python-is-python3 \
     && \
     apt-get clean && \
     rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
 
 # Install Python packages (via pip)
-RUN pip3 install --no-cache-dir meshio>=4.0.16 "numpy>=1.21,<1.23" && \
-    pip3 install --upgrade six
+RUN python3 -m pip install --no-cache-dir meshio numpy matplotlib
 
 # Install Basix
 RUN git clone --depth 1 --branch ${FENICSX_BASIX_TAG} https://github.com/FEniCS/basix.git basix-src && \
@@ -302,12 +188,11 @@ RUN git clone --depth 1 --branch ${FENICSX_BASIX_TAG} https://github.com/FEniCS/
     cmake -G Ninja -DCMAKE_BUILD_TYPE=Release -B build-dir -S . && \
     cmake --build build-dir && \
     cmake --install build-dir && \
-    pip3 install ./python
+    python3 -m pip install ./python
 
 # Install FEniCSx components
-RUN pip3 install --no-cache-dir ipython && \
-    pip3 install --no-cache-dir git+https://github.com/FEniCS/ufl.git@${FENICSX_UFL_TAG} && \
-    pip3 install --no-cache-dir git+https://github.com/FEniCS/ffcx.git@${FENICSX_FFCX_TAG}
+RUN python3 -m pip install --no-cache-dir git+https://github.com/FEniCS/ufl.git@${FENICSX_UFL_TAG} && \
+    python3 -m pip install --no-cache-dir git+https://github.com/FEniCS/ffcx.git@${FENICSX_FFCX_TAG}
 
 # Install FEniCSx
 RUN git clone --depth 1 --branch ${FENICSX_DOLFINX_TAG} https://github.com/fenics/dolfinx.git && \
@@ -318,7 +203,7 @@ RUN git clone --depth 1 --branch ${FENICSX_DOLFINX_TAG} https://github.com/fenic
     ninja ${DOLFINX_MAKEFLAGS} install && \
     . /usr/local/dolfinx-complex/lib/dolfinx/dolfinx.conf && \
     cd ../python && \
-    PETSC_ARCH=linux-gnu-complex-32 pip3 install --target /usr/local/dolfinx-complex/lib/python3.8/dist-packages --no-dependencies --ignore-installed .
+    PETSC_ARCH=linux-gnu-complex-32 python3 -m pip install --target /usr/local/dolfinx-complex/lib/python3.8/dist-packages --no-dependencies --ignore-installed .
 
 # complex by default.
 ENV LD_LIBRARY_PATH=/usr/local/dolfinx-complex/lib:$LD_LIBRARY_PATH \
@@ -331,7 +216,7 @@ ENV LD_LIBRARY_PATH=/usr/local/dolfinx-complex/lib:$LD_LIBRARY_PATH \
 RUN wget -nc --quiet https://github.com/exafmm/exafmm-t/archive/v${EXAFMM_VERSION}.tar.gz && \
     tar -xf v${EXAFMM_VERSION}.tar.gz && \
     cd exafmm-t-${EXAFMM_VERSION} && \
-    sed -i 's/march=native/march=ivybridge/g' ./setup.py && python3 setup.py install
+    sed -i 's/march=native/march=ivybridge/g' ./setup.py && python3 -m pip install .
 
 # Clear /tmp
 RUN rm -rf /tmp/*
@@ -345,21 +230,7 @@ LABEL description="Bempp-cl environment with FEniCSx"
 
 WORKDIR /tmp
 RUN git clone https://github.com/bempp/bempp-cl
-RUN cd bempp-cl && python3 setup.py install
-
-# Clear /tmp
-RUN rm -rf /tmp/*
-
-WORKDIR /root
-
-########################################
-
-FROM bempp-dev-env-with-dolfin as with-dolfin
-LABEL description="Bempp-cl environment with FEniCS"
-
-WORKDIR /tmp
-RUN git clone https://github.com/bempp/bempp-cl
-RUN cd bempp-cl && python3 setup.py install
+RUN cd bempp-cl && python3 -m pip install .
 
 # Clear /tmp
 RUN rm -rf /tmp/*
@@ -373,7 +244,7 @@ LABEL description="Bempp Jupyter Lab"
 
 WORKDIR /tmp
 RUN git clone https://github.com/bempp/bempp-cl
-RUN cd bempp-cl && python3 setup.py install
+RUN cd bempp-cl && python3 -m pip install .
 RUN cp -r bempp-cl/notebooks /root/example_notebooks
 RUN rm /root/example_notebooks/conftest.py /root/example_notebooks/test_notebooks.py
 
@@ -385,7 +256,7 @@ WORKDIR /root
 ARG TINI_VERSION
 ADD https://github.com/krallin/tini/releases/download/v${TINI_VERSION}/tini /tini
 RUN chmod +x /tini && \
-    pip3 install --no-cache-dir jupyter jupyterlab plotly
+    python3 -m pip install --no-cache-dir jupyter jupyterlab plotly
 EXPOSE 8888/tcp
 
 ENTRYPOINT ["/tini", "--", "jupyter", "lab", "--ip", "0.0.0.0", "--no-browser", "--allow-root"]
@@ -397,31 +268,7 @@ LABEL description="Bempp Jupyter Lab (Numba only)"
 
 WORKDIR /tmp
 RUN git clone https://github.com/bempp/bempp-cl
-RUN cd bempp-cl && python3 setup.py install
-RUN cp -r bempp-cl/notebooks /root/example_notebooks
-RUN rm /root/example_notebooks/conftest.py /root/example_notebooks/test_notebooks.py
-
-# Clear /tmp
-RUN rm -rf /tmp/*
-
-WORKDIR /root
-
-ARG TINI_VERSION
-ADD https://github.com/krallin/tini/releases/download/v${TINI_VERSION}/tini /tini
-RUN chmod +x /tini && \
-    pip3 install --no-cache-dir jupyter jupyterlab plotly
-EXPOSE 8888/tcp
-
-ENTRYPOINT ["/tini", "--", "jupyter", "lab", "--ip", "0.0.0.0", "--no-browser", "--allow-root"]
-
-########################################
-
-FROM bempp-dev-env-with-dolfin as fenics-lab
-LABEL description="Bempp Jupyter Lab with legacy FEniCS"
-
-WORKDIR /tmp
-RUN git clone https://github.com/bempp/bempp-cl
-RUN cd bempp-cl && pip3 install .
+RUN cd bempp-cl && python3 -m pip install .
 RUN cp -r bempp-cl/notebooks /root/example_notebooks
 RUN rm /root/example_notebooks/conftest.py /root/example_notebooks/test_notebooks.py
 
@@ -433,7 +280,7 @@ WORKDIR /root
 ARG TINI_VERSION
 ADD https://github.com/krallin/tini/releases/download/v${TINI_VERSION}/tini /tini
 RUN chmod +x /tini && \
-    pip3 install --no-cache-dir jupyter jupyterlab plotly
+    python3 -m pip install --no-cache-dir jupyter jupyterlab plotly
 EXPOSE 8888/tcp
 
 ENTRYPOINT ["/tini", "--", "jupyter", "lab", "--ip", "0.0.0.0", "--no-browser", "--allow-root"]
diff --git a/bempp/api/assembly/blocked_operator.py b/bempp/api/assembly/blocked_operator.py
index 67544a88..06907b91 100644
--- a/bempp/api/assembly/blocked_operator.py
+++ b/bempp/api/assembly/blocked_operator.py
@@ -156,7 +156,7 @@ def __init__(self, m, n):
         """Construct an (m x n) blocked boundary operator."""
         super().__init__()
 
-        self._operators = _np.empty((m, n), dtype=_np.object)
+        self._operators = _np.empty((m, n), dtype=object)
         self._rows = m * [False]
         self._cols = n * [False]
 
@@ -592,7 +592,7 @@ def __init__(self, ops):
 
         self._ndims = (rows, cols)
 
-        self._operators = _np.empty((rows, cols), dtype=_np.object)
+        self._operators = _np.empty((rows, cols), dtype=object)
         self._rows = -_np.ones(rows, dtype=int)
         self._cols = -_np.ones(cols, dtype=int)
 
diff --git a/bempp/api/utils/remote_operator.py b/bempp/api/utils/remote_operator.py
index f2f48ad3..36763d90 100644
--- a/bempp/api/utils/remote_operator.py
+++ b/bempp/api/utils/remote_operator.py
@@ -272,7 +272,7 @@ def __init__(self, ops):
 
         self._ndims = (rows, cols)
 
-        self._operators = _np.empty((rows, cols), dtype=_np.object)
+        self._operators = _np.empty((rows, cols), dtype=object)
         self._tags = _np.empty((rows, cols), dtype=_np.int)
         self._rows = -_np.ones(rows, dtype=int)
         self._cols = -_np.ones(cols, dtype=int)