diff --git a/.travis.yml b/.travis.yml
index 0c97752f62b074450f7a8a929f240682a9a96f9c..b84b84a5aafcfc5740a2dcfa1a6641fbfdcc9da3 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -36,6 +36,9 @@ addons:
     - libtommath-dev
 
 
+before_install:
+  - if [ "$CC" = "clang" ]; then WEXTRAFLAGS="$WEXTRAFLAGS -Wno-error=incompatible-library-redeclaration" ; fi  # workaround
+
 install:
   - if [ "$TRAVIS_OS_NAME" = "osx" -a "$BUNDLEDLIBTOM" != "--enable-bundled-libtom" ]; then brew update > /dev/null && brew install libtomcrypt libtommath ; fi