diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 95a76abcd..39e0af892 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -38,34 +38,35 @@ jobs:
       Python35Linux:
         imageName: 'ubuntu-16.04'
         python.version: '3.5'
+        os: linux
       Python35Windows:
         imageName: 'vs2017-win2016'
         python.version: '3.5'
+# Test on one OS per python 3.6/3.7/3.8 to speed up CI
       Python36Linux:
         imageName: 'ubuntu-16.04'
         python.version: '3.6'
-      Python36Windows:
-        imageName: 'vs2017-win2016'
-        python.version: '3.6'
-      Python36Mac:
-        imageName: 'macos-10.14'
-        python.version: '3.6'
-      # Don't test on 3.7 for now to speed up builds
-      Python37Linux:
-        imageName: 'ubuntu-16.04'
-        python.version: '3.7'
+#      Python36Windows:
+#        imageName: 'vs2017-win2016'
+#        python.version: '3.6'
+#      Python36Mac:
+#        imageName: 'macos-10.14'
+#        python.version: '3.6'
+#      Python37Linux:
+#        imageName: 'ubuntu-16.04'
+#        python.version: '3.7'
       Python37Windows:
         imageName: 'vs2017-win2016'
         python.version: '3.7'
-      Python37Mac:
-        imageName: 'macos-10.14'
-        python.version: '3.7'
-      Python38Linux:
-        imageName: 'ubuntu-16.04'
-        python.version: '3.8'
-      Python38Windows:
-        imageName: 'vs2017-win2016'
-        python.version: '3.8'
+#      Python37Mac:
+#        imageName: 'macos-10.14'
+#        python.version: '3.7'
+#      Python38Linux:
+#        imageName: 'ubuntu-16.04'
+#        python.version: '3.8'
+#      Python38Windows:
+#        imageName: 'vs2017-win2016'
+#        python.version: '3.8'
       Python38Mac:
         imageName: 'macos-10.14'
         python.version: '3.8'
@@ -108,9 +109,14 @@ jobs:
       pip uninstall -y -r installed.txt
     displayName: 'Uninstall all packages'
 
+  - script: |
+      pip install wheel
+    condition: and(eq(variables['os'], 'linux'), eq(variables['python.version'], '3.5'))
+    displayName: 'Hack: install wheel for python 3.5'
+
   - bash: |
       SDIST=$(python -c "import os;print(os.listdir('./dist')[-1])" 2>&1)
-      pip install dist/$SDIST --only-binary :all:
+      pip install dist/$SDIST
     displayName: 'Install from sdist'
 
   - script: |
diff --git a/pyproject.toml b/pyproject.toml
index 48e0e21c4..f991fe404 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -6,9 +6,8 @@ requires = [
     "preshed>=3.0.2,<3.1.0",
     "murmurhash>=0.28.0,<1.1.0",
     "thinc>=7.4.1,<7.5.0",
-    "numpy==1.15.0; python_version<='3.7'",
-    "numpy==1.17.3; python_version=='3.8'",
-    "numpy==1.19.3; python_version=='3.9'",
-    "numpy; python_version>='3.10'",
+    "blis>=0.4.0,<0.8.0; python_version >= '3.6'",
+    "blis>=0.4.0,<0.5.0; python_version < '3.6'",
+    "numpy>=1.15.0",
 ]
 build-backend = "setuptools.build_meta"
diff --git a/setup.cfg b/setup.cfg
index 4e8164d39..7c921f02c 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -40,6 +40,7 @@ setup_requires =
     preshed>=3.0.2,<3.1.0
     murmurhash>=0.28.0,<1.1.0
     thinc>=7.4.1,<7.5.0
+    blis>=0.4.0,<0.8.0
 install_requires =
     # Our libraries
     murmurhash>=0.28.0,<1.1.0