diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index dd20d992..1bbe583e 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -5,6 +5,10 @@ trigger:
     include:
       - main
       - maint/*
+pr:
+  branches:
+    include:
+      - '*'  # must quote since "*" is a YAML reserved character; we want a string
 
 jobs:
   - job: Windows