diff --git a/.travis.yml b/.travis.yml
index 9584d3869..bf69573aa 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -17,8 +17,13 @@ env:
 ###############################################################################
 # Ubuntu 16.04 LTS
 ###############################################################################
+    # FIXME: We should probably do unoptimized build to avoid the compiler's
+    # optimizer removing bad behaviour. However we can't run the unit tests
+    # if we do a Debug build because they are too slow.
     # 64-bit UBSan build
     - LINUX_BASE=ubuntu_16.04 C_COMPILER=/usr/bin/clang-3.9 CXX_COMPILER=/usr/bin/clang++-3.9 TARGET_ARCH=x86_64 Z3_BUILD_TYPE=RelWithDebInfo UBSAN_BUILD=1
+    # 64-bit ASan build
+    - LINUX_BASE=ubuntu_16.04 C_COMPILER=/usr/bin/clang-3.9 CXX_COMPILER=/usr/bin/clang++-3.9 TARGET_ARCH=x86_64 Z3_BUILD_TYPE=RelWithDebInfo ASAN_BUILD=1
 
     # 64-bit GCC 5.4 RelWithDebInfo
     - LINUX_BASE=ubuntu_16.04 C_COMPILER=/usr/bin/gcc-5 CXX_COMPILER=/usr/bin/g++-5 TARGET_ARCH=x86_64 Z3_BUILD_TYPE=RelWithDebInfo