diff --git a/.travis.yml b/.travis.yml
index d8413fcb974..6e4715682de 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -9,7 +9,7 @@ branches:
 env:
   global:
     - DISCOURSE_HOSTNAME=www.example.com
-    - RUBY_GC_MALLOC_LIMIT=50000000
+    - RUBY_GLOBAL_METHOD_CACHE_SIZE=131072
   matrix:
     - "RAILS_MASTER=0 QUNIT_RUN=0 RUN_LINT=0"
     - "RAILS_MASTER=0 QUNIT_RUN=1 RUN_LINT=0"
@@ -17,7 +17,7 @@ env:
 
 addons:
   chrome: stable
-  postgresql: 9.5
+  postgresql: 10
   apt:
     packages:
     - gifsicle