diff --git a/.github/workflows/linux.yml b/.github/workflows/linux.yml
index 54dcd7b0b3..0e42a0d349 100644
--- a/.github/workflows/linux.yml
+++ b/.github/workflows/linux.yml
@@ -21,6 +21,8 @@ on:
 env:
   MARGS: "-j2"
   CFLAGS: "-g"
+  # This will need updating as the ubuntu-latest image changes:
+  PHP_FPM: "/usr/sbin/php-fpm8.1"
 
 jobs:
   build: