diff --git a/.platform.app.yaml b/.platform.app.yaml
index e8d8272954..936feda6bb 100644
--- a/.platform.app.yaml
+++ b/.platform.app.yaml
@@ -8,7 +8,7 @@
 name: app
 
 # The type of the application to build.
-type: php:7.3
+type: php:7.2
 build:
     # "none" means we're running composer manually, see build hook
     flavor: "none"