diff --git a/.travis.yml b/.travis.yml
index 350bf13..2834f8b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -254,7 +254,8 @@ matrix:
       env: TOOLSET=clang COMPILER=clang++ CXXSTD=03,11,14,1z
 
 install:
-  - BOOST_BRANCH=develop && [ "$TRAVIS_BRANCH" == "master" ] && BOOST_BRANCH=master || true
+  - BOOST_BRANCH=develop
+  - if [ "$TRAVIS_BRANCH" = "master" ]; then BOOST_BRANCH=master; fi
   - cd ..
   - git clone -b $BOOST_BRANCH https://github.com/boostorg/boost.git boost-root
   - cd boost-root