diff --git a/.travis.yml b/.travis.yml
index e2f1ba637..3fc35eba1 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -32,7 +32,10 @@ script:
 # download clang git, compile cppcheck, run cppcheck on clang code to look for crashes in cppcheck. if this is done, terminate build
   - if [[ "$CHECK_CLANG" == "yes" ]] && [[ "$CC" == "gcc" ]]; then wget "https://github.com/llvm-mirror/clang/archive/817ee21333dffb3c77ef845aa1a9f8d1dc94a842.zip" & make -j 4 & wait; unzip 817ee21333dffb3c77ef845aa1a9f8d1dc94a842.zip > /dev/null; touch /tmp/clang.cppcheck; cd ./clang-817ee21333dffb3c77ef845aa1a9f8d1dc94a842 ; ../cppcheck . --max-configs=1 --enable=all --inconclusive --exception-handling -iINPUTS -j 2 |& tee /tmp/clang.cppcheck; cd ../ ; ! grep "process crashed with signal\|Internal error\. compiled" /tmp/clang.cppcheck; exit; fi
 # compile cppcheck, default build
-  - make -j4
+  - make clean
+  - make test -j4 CPPFLAGS=-DTEST_MATHLIB_VALUE
+  - touch lib/mathlib.cpp
+  - touch test/testmathlib.cpp
   - make test -j4
 # compile gui
   - cd gui