diff --git a/phpunit.xml b/phpunit.xml
index 48397e6..07acc42 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -18,6 +18,10 @@
         </include>
     </source>
     <php>
+        <!-- The suite, not any one test, outgrew PHP's usual 128M: the panel
+             tests boot Filament again and again in one process. Stated here so
+             it runs the same on every machine, whatever its php.ini says. -->
+        <ini name="memory_limit" value="512M"/>
         <env name="APP_ENV" value="testing"/>
         <env name="APP_MAINTENANCE_DRIVER" value="file"/>
         <env name="BCRYPT_ROUNDS" value="4"/>