diff --git a/Dockerfile b/Dockerfile
index 3b4eb15..f0cd962 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -72,6 +72,8 @@ RUN { \
         echo 'opcache.max_accelerated_files=4000'; \
         echo 'opcache.revalidate_freq=60'; \
         echo 'opcache.fast_shutdown=1'; \
+        # From Phabricator
+        echo 'opcache.validate_timestamps=0'; \
     } > /usr/local/etc/php/conf.d/opcache-recommended.ini
 
 # Set the default timezone.
diff --git a/Dockerfile.daemon b/Dockerfile.daemon
index f358ca1..38f4b97 100644
--- a/Dockerfile.daemon
+++ b/Dockerfile.daemon
@@ -67,6 +67,8 @@ RUN { \
         echo 'opcache.max_accelerated_files=4000'; \
         echo 'opcache.revalidate_freq=60'; \
         echo 'opcache.fast_shutdown=1'; \
+        # From Phabricator
+        echo 'opcache.validate_timestamps=0'; \
     } > /usr/local/etc/php/conf.d/opcache-recommended.ini
 
 # Set the default timezone.