diff --git a/.travis.yml b/.travis.yml
index 53bc090e02..fd46c30928 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -13,6 +13,7 @@ rust: stable
 env:
   global:
     - CRATE_NAME=nix
+    - RUST_TEST_THREADS=1
 
     # default job
     - TARGET=x86_64-unknown-linux-gnu