diff --git a/travis_custom/custom_build b/travis_custom/custom_build
index 1351351619862f8d005b8ddad44d74b264666703..4c3cf67e2a4daaf5468faadcbe362aa441281d06 100755
--- a/travis_custom/custom_build
+++ b/travis_custom/custom_build
@@ -2,7 +2,7 @@
 set -e
 
 # Setup environment variables.
-export CMAKE_ADDITIONAL_OPTIONS=" ${CMAKE_ADDITIONAL_OPTIONS} -DBUILD_BENCHMARK=\"ON\" -DBUILD_UNIT_TESTS=\"ON\" -DCMAKE_CXX_FLAGS=-DBOOST_SYSTEM_NO_DEPRECATED"
+export CMAKE_ADDITIONAL_OPTIONS=" ${CMAKE_ADDITIONAL_OPTIONS} -DBUILD_BENCHMARK=\"ON\" -DBUILD_TESTING=\"ON\" -DCMAKE_CXX_FLAGS=-DBOOST_SYSTEM_NO_DEPRECATED"
 if [[ ";${DO_INSTALL_DOC_EXCEPT_ON_BRANCH};" == *";${CI_BRANCH};"* ]]; then
   export CMAKE_ADDITIONAL_OPTIONS=" ${CMAKE_ADDITIONAL_OPTIONS} -DINSTALL_DOCUMENTATION=\"OFF\""
 else
@@ -11,6 +11,7 @@ fi
 
 if [[ $TRAVIS_PYTHON_VERSION -gt 30 ]]; then
   export CMAKE_ADDITIONAL_OPTIONS=" ${CMAKE_ADDITIONAL_OPTIONS} -DPYTHON_EXECUTABLE=$(which python3)"
+  pip3 install numpy --user
 fi
 
 # Setup environment variables.