diff --git a/.travis.yml b/.travis.yml
index 96f4c53..dbd1ff7 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -63,11 +63,6 @@ matrix:
     - env: TOOLSET=clang-3.9
     - env: TOOLSET=clang-4.0
     - env: TOOLSET=clang-5.0
-    - env: TOOLSET=clang-6.0 CXXFLAGS=-std=c++03
-    - env: TOOLSET=clang-6.0 CXXFLAGS=-std=c++11
-    - env: TOOLSET=clang-6.0 CXXFLAGS=-std=c++14
-    - env: TOOLSET=clang-6.0 CXXFLAGS=-std=c++17
-    - env: TOOLSET=clang-6.0 CXXFLAGS=-std=c++2a
     - env: TOOLSET=gcc-4.7
     - env: TOOLSET=gcc-4.8
     - env: TOOLSET=gcc-4.9