diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 9c3b92f06..c75d1396f 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -25,7 +25,7 @@ jobs:
   # defined in .flake8 and overwrites the selected codes.
   - job: "Validate"
     pool:
-      vmImage: "ubuntu-latest"
+      vmImage: "ubuntu-20.04"
     steps:
       - task: UsePythonVersion@0
         inputs:
@@ -41,7 +41,7 @@ jobs:
       matrix:
         # We're only running one platform per Python version to speed up builds
         Python36Linux:
-          imageName: "ubuntu-latest"
+          imageName: "ubuntu-20.04"
           python.version: "3.6"
         #        Python36Windows:
         #          imageName: "windows-latest"
@@ -50,7 +50,7 @@ jobs:
         #          imageName: "macos-latest"
         #          python.version: "3.6"
         #        Python37Linux:
-        #          imageName: "ubuntu-latest"
+        #          imageName: "ubuntu-20.04"
         #          python.version: "3.7"
         Python37Windows:
           imageName: "windows-latest"
@@ -59,7 +59,7 @@ jobs:
         #          imageName: "macos-latest"
         #          python.version: "3.7"
         #        Python38Linux:
-        #          imageName: "ubuntu-latest"
+        #          imageName: "ubuntu-20.04"
         #          python.version: "3.8"
         #        Python38Windows:
         #          imageName: "windows-latest"
@@ -68,7 +68,7 @@ jobs:
           imageName: "macos-latest"
           python.version: "3.8"
         Python39Linux:
-          imageName: "ubuntu-latest"
+          imageName: "ubuntu-20.04"
           python.version: "3.9"
         #        Python39Windows:
         #          imageName: "windows-latest"
@@ -77,7 +77,7 @@ jobs:
         #          imageName: "macos-latest"
         #          python.version: "3.9"
         #        Python310Linux:
-        #          imageName: "ubuntu-latest"
+        #          imageName: "ubuntu-20.04"
         #          python.version: "3.10"
         Python310Windows:
           imageName: "windows-latest"
@@ -86,7 +86,7 @@ jobs:
         #          imageName: "macos-latest"
         #          python.version: "3.10"
         Python311Linux:
-          imageName: 'ubuntu-latest'
+          imageName: 'ubuntu-20.04'
           python.version: '3.11'
         Python311Windows:
           imageName: 'windows-latest'