diff --git a/.azure/azure-ci-build-pipeline.yaml b/.azure/azure-ci-build-pipeline.yaml
index 902eb38d..fe50fb32 100644
--- a/.azure/azure-ci-build-pipeline.yaml
+++ b/.azure/azure-ci-build-pipeline.yaml
@@ -11,21 +11,27 @@ strategy:
     UbuntuPython38:
       python.version: '3.8'
       imageName: 'ubuntu-latest'
+      condition: eq(variables['Build.Reason'], 'PullRequest')
     UbuntuPython310:
       python.version: '3.10'
       imageName: 'ubuntu-latest'
     WindowsPython38:
       python.version: '3.8'
       imageName: 'windows-latest'
+      condition: eq(variables['Build.Reason'], 'PullRequest')
     WindowsPython310:
       python.version: '3.10'
       imageName: 'windows-latest'
+      condition: eq(variables['Build.Reason'], 'PullRequest')
     MacOSPython38:
       python.version: '3.8'
       imageName: 'macOS-latest'
+      condition: eq(variables['Build.Reason'], 'PullRequest')
     MacOSPython310:
       python.version: '3.10'
       imageName: 'macOS-latest'
+      condition: eq(variables['Build.Reason'], 'PullRequest')
+      # pretty sure this does not support a 'condition' parameter but worth a try. Otherwise a more complicated solution might be warranted.
 
 pool:
   vmImage: $(imageName)