diff --git a/.circleci/config.yml b/.circleci/config.yml
index 4b46f08..233ca2f 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -43,7 +43,7 @@ jobs:
   python:
     working_directory: ~/repo
     docker:
-      - image: konstin2/pyo3-pack:0.5.0
+      - image: konstin2/maturin:v0.8.2-alpha.1
     steps:
       - checkout
       - run:
@@ -54,11 +54,12 @@ jobs:
       - run:
           name: build-wheels
           command: |
+            set -ex
             cd python
-            for PYBIN in python3.{6,7}; do
-                "$PYBIN" -m pip install setuptools setuptools-rust>=0.10.2
-                "$PYBIN" -m pip install numpy==1.15.0 scipy==1.1.0
+            export PATH="$PATH:/opt/python/cp38-cp38m/bin/"
+            for PYBIN in python3.{6,7,8}; do
                 "$PYBIN" -m pip install wheel==0.31.1 auditwheel==2.0.0 pytest hypothesis
+                "$PYBIN" -m pip install -r ../ci/requirements-build.txt
                 "$PYBIN" setup.py bdist_wheel
             done
             for whl in dist/*.whl; do
@@ -68,8 +69,10 @@ jobs:
       - run:
           name: test
           command: |
+            set -ex
             cd python
-            for PYBIN in python3.{6,7}; do
+            export PATH="$PATH:/opt/python/cp38-cp38m/bin/"
+            for PYBIN in python3.{6,7,8}; do
                 "$PYBIN" -m pip uninstall -y vtext
                 cd /tmp/
                 "$PYBIN" -m pip install --pre --no-index --find-links /root/repo/python/dist/ vtext
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 85da7f0..6a9f772 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -4,13 +4,17 @@ jobs:
 - template: ci/azure/posix.yml
   parameters:
     name: macOS
-    vmImage: xcode9-macos10.13
+    vmImage: macOS-10.14
     matrix:
+      py38:
+        PYTHON_VERSION: '3.8'
+        PYTHON_ARCH: '64'
       py37:
         PYTHON_VERSION: '3.7'
+        PYTHON_ARCH: '64'
       py36:
         PYTHON_VERSION: '3.6'
-
+        PYTHON_ARCH: '64'
 
 - template: ci/azure/windows.yml
   parameters:
diff --git a/ci/azure/install.cmd b/ci/azure/install.cmd
index 625fa2f..cbd23e5 100644
--- a/ci/azure/install.cmd
+++ b/ci/azure/install.cmd
@@ -17,19 +17,19 @@ call activate %VIRTUALENV%
 python --version
 pip --version
 
-@rem Use oldest supported numpy and scipy versions for building wheels
-pip install numpy==1.15.0 scipy==1.1.0 pytest>=4.0.0 wheel>=0.31.1 hypothesis
+pip install scipy==1.4.1 pytest>=4.0.0 wheel>=0.31.1 hypothesis
 
 curl -sSf -o rustup-init.exe https://win.rustup.rs
 rustup-init.exe -y --default-toolchain nightly-2019-11-01
 set PATH=%PATH%;%USERPROFILE%\.cargo\bin
 echo "##vso[task.setvariable variable=PATH;]%PATH%;%USERPROFILE%\.cargo\bin"
 
+rustup set default-host x86_64-pc-windows-gnu
 rustup default nightly-2019-11-01
 
 @rem Install the build and runtime dependencies of the project.
 cd python/
-pip install -r requirements.txt
+python -m pip install -r ..\ci\requirements-build.txt
 python setup.py bdist_wheel
 
 pip install pytest-faulthandler
diff --git a/ci/azure/install.sh b/ci/azure/install.sh
index 351842f..10acbfe 100755
--- a/ci/azure/install.sh
+++ b/ci/azure/install.sh
@@ -1,6 +1,6 @@
 #!/bin/bash
 
-set -e
+set -ex
 
 UNAMESTR=`uname`
 
@@ -12,8 +12,7 @@ source activate $VIRTUALENV
 python --version
 pip --version
 
-# Use oldest supported numpy, scipy versins for building wheels
-pip install numpy==1.15.0 scipy==1.1.0 pytest>=4.0.0 wheel>=0.31.1 hypothesis
+pip install scipy==1.1.0 pytest>=4.0.0 wheel>=0.31.1 hypothesis
 
 python -c "import numpy; print('numpy %s' % numpy.__version__)"
 python -c "import scipy; print('scipy %s' % scipy.__version__)"
@@ -21,9 +20,10 @@ pip list
 
 curl https://sh.rustup.rs -sSf | sh -s -- -y --default-toolchain nightly-2019-11-01
 source $HOME/.cargo/env
+rustup default nightly-2019-11-01
 
 cd python/
-pip install -r requirements.txt
+python -m pip install -r ../ci/requirements-build.txt
 python setup.py bdist_wheel
 
 pip install --pre --no-index --find-links dist/ vtext
diff --git a/ci/azure/posix.yml b/ci/azure/posix.yml
index 9cb6372..a012e1a 100644
--- a/ci/azure/posix.yml
+++ b/ci/azure/posix.yml
@@ -20,6 +20,8 @@ jobs:
   steps:
     - bash: echo "##vso[task.prependpath]$CONDA/bin"
       displayName: Add conda to PATH
+    # fix permissions on MacOS
+    - script: sudo chown -R 501:20 /usr/local/miniconda/
     - script: |
         ci/azure/install.sh
       displayName: 'Install'
diff --git a/ci/requirements-build.txt b/ci/requirements-build.txt
new file mode 100644
index 0000000..176871f
--- /dev/null
+++ b/ci/requirements-build.txt
@@ -0,0 +1,5 @@
+setuptools
+wheel
+setuptools-rust
+numpy==1.17.3
+scipy==1.4.1
diff --git a/python/pyproject.toml b/python/pyproject.toml
index 31ffe04..dc1adc8 100644
--- a/python/pyproject.toml
+++ b/python/pyproject.toml
@@ -1,2 +1,9 @@
 [build-system]
-requires = ["setuptools", "wheel", "setuptools-rust"]
+requires = [
+    "setuptools",
+    "wheel",
+    "setuptools-rust",
+    "numpy==1.13.3; python_version=='3.6'",
+    "numpy==1.14.5; python_version=='3.7'",
+    "numpy==1.17.3; python_version>='3.8'",
+]
diff --git a/python/setup.py b/python/setup.py
index 2b14f19..75ba2c8 100644
--- a/python/setup.py
+++ b/python/setup.py
@@ -16,7 +16,6 @@
     rust_extensions=[
         RustExtension(
             "vtext._lib",
-            "./Cargo.toml",
             rustc_flags=["--cfg=Py_3"],
             features=["numpy/python3"],
             args=["--no-default-features"],