diff --git a/.appveyor.yml b/.appveyor.yml
index 794a9d97928b2e703a3197e7a23991c4e59bb885..72aa6bda28315ede4a5f6123de515e0db91d512a 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -25,7 +25,7 @@ install:
   - set PATH=%MINICONDA%;%MINICONDA%\\Scripts;%PATH%
   - conda config --set always_yes yes --set changeps1 no
   - conda info -a
-  - conda create -q -n test-environment python=%PYTHON_VERSION% numpy scipy Cython
+  - conda create -q -n test-environment python=%PYTHON_VERSION% numpy<1.20 scipy Cython
   - activate test-environment
   - python -m pip install --upgrade pip
   - pip install wheel twine pytest
diff --git a/.circleci/config.yml b/.circleci/config.yml
index 2e17815acec67ea09a9d16a313aea0547e87f0f4..fc50702ba23b46b0538c16d373540378acb32386 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -18,7 +18,7 @@ jobs:
           no_output_timeout: 30m
           command: |
             sudo pip install --upgrade pip
-            sudo pip install --only-binary=numpy,scipy numpy scipy Cython pytest pytest-cov codecov
+            sudo pip install --only-binary=numpy,scipy numpy<1.20 scipy Cython pytest pytest-cov codecov
             sudo pip install -e .[tests]
       - save_cache:
           key: deps9-{{ .Branch }}
diff --git a/.github/workflows/python-package.yml b/.github/workflows/python-package.yml
index e084c1e7b020bc7a60dbe34dd683dcd7ba3dc311..59531d2f7f5ed0f08b2a40e80792a285cd693365 100644
--- a/.github/workflows/python-package.yml
+++ b/.github/workflows/python-package.yml
@@ -29,7 +29,7 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        python -m pip install --only-binary=numpy,scipy numpy scipy Cython pytest pytest-cov codecov flake8
+        python -m pip install --only-binary=numpy,scipy numpy<1.20 scipy Cython pytest pytest-cov codecov flake8
         python -m pip install -e .[tests]
         if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
     - name: Lint with flake8
diff --git a/.github/workflows/python-publish.yml b/.github/workflows/python-publish.yml
index 0a5aa952de8230a50355b42277e3b6ad7a402abe..da509fad999a503039ab2c3ea40ddbe04c23ba9c 100644
--- a/.github/workflows/python-publish.yml
+++ b/.github/workflows/python-publish.yml
@@ -80,7 +80,7 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        python -m pip install --only-binary=numpy,scipy numpy scipy Cython wheel
+        python -m pip install --only-binary=numpy,scipy numpy<1.20 scipy Cython wheel
 
     - name: Build source tar file
       run: python setup.py sdist