diff --git a/.travis.yml b/.travis.yml
index 17498310..b100a600 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,7 +2,7 @@ language: ruby
 env:
   global:
     - RUBY_GC_MALLOC_LIMIT=90000000
-    - RUBY_FREE_MIN=200000
+    - RUBY_GC_HEAP_FREE_SLOTS=200000
 rvm:
   - 2.1.0
 addons: