diff --git a/.travis.yml b/.travis.yml
index 29f26cf0..c32943a0 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -24,7 +24,7 @@ matrix:
       addons:
         apt:
           sources:
-	    - ubuntu-toolchain-r-test
+            - ubuntu-toolchain-r-test
             - llvm-toolchain-trusty-5.0
           packages:
             - clang-5.0