diff --git a/.travis.yml b/.travis.yml
index b694777b8..ae69db370 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -24,11 +24,12 @@ env:
     # clang
     #too slow; times out: - LINUX_BASE=ubuntu_18.04 C_COMPILER=clang CXX_COMPILER=clang++ TARGET_ARCH=x86_64 Z3_BUILD_TYPE=Debug UBSAN_BUILD=1 RUN_UNIT_TESTS=BUILD_AND_RUN
     - LINUX_BASE=ubuntu_18.04 C_COMPILER=clang CXX_COMPILER=clang++ TARGET_ARCH=x86_64 Z3_BUILD_TYPE=Debug ASAN_BUILD=1 RUN_UNIT_TESTS=BUILD_AND_RUN
+    - LINUX_BASE=ubuntu_18.04 C_COMPILER=clang CXX_COMPILER=clang++ TARGET_ARCH=x86_64 Z3_BUILD_TYPE=Release UBSAN_BUILD=1 RUN_UNIT_TESTS=BUILD_AND_RUN
     - LINUX_BASE=ubuntu_18.04 C_COMPILER=clang CXX_COMPILER=clang++ TARGET_ARCH=x86_64 Z3_BUILD_TYPE=RelWithDebInfo ASAN_BUILD=1 RUN_UNIT_TESTS=BUILD_AND_RUN UBSAN_BUILD=1 RUN_API_EXAMPLES=0 RUN_SYSTEM_TESTS=0 DOTNET_BINDINGS=0 JAVA_BINDINGS=0 PYTHON_BINDINGS=0
 
     # gcc
-    - LINUX_BASE=ubuntu_18.04 C_COMPILER=gcc CXX_COMPILER=g++ TARGET_ARCH=x86_64 Z3_BUILD_TYPE=Release RUN_UNIT_TESTS=BUILD_AND_RUN
-    - LINUX_BASE=ubuntu_18.04 C_COMPILER=gcc CXX_COMPILER=g++ TARGET_ARCH=x86_64 Z3_BUILD_TYPE=Debug UBSAN_BUILD=1 RUN_UNIT_TESTS=BUILD_AND_RUN
+    - LINUX_BASE=ubuntu_18.04 C_COMPILER=gcc CXX_COMPILER=g++ TARGET_ARCH=x86_64 Z3_BUILD_TYPE=Release UBSAN_BUILD=1 RUN_UNIT_TESTS=BUILD_AND_RUN
+    - LINUX_BASE=ubuntu_18.04 C_COMPILER=gcc CXX_COMPILER=g++ TARGET_ARCH=x86_64 Z3_BUILD_TYPE=Debug RUN_UNIT_TESTS=BUILD_AND_RUN
     # 18.04's gcc asan lib doesn't support pthread_atfork. TODO: enable for ubuntu 20.04
     #- LINUX_BASE=ubuntu_18.04 C_COMPILER=gcc CXX_COMPILER=g++ TARGET_ARCH=x86_64 Z3_BUILD_TYPE=Debug ASAN_BUILD=1 RUN_UNIT_TESTS=BUILD_AND_RUN
 
diff --git a/contrib/ci/Dockerfiles/z3_build.Dockerfile b/contrib/ci/Dockerfiles/z3_build.Dockerfile
index 6f8c236c5..f513ea74b 100644
--- a/contrib/ci/Dockerfiles/z3_build.Dockerfile
+++ b/contrib/ci/Dockerfiles/z3_build.Dockerfile
@@ -12,7 +12,7 @@ ARG DOTNET_BINDINGS
 ARG JAVA_BINDINGS
 ARG NO_SUPPRESS_OUTPUT
 ARG PYTHON_BINDINGS
-ARG PYTHON_EXECUTABLE=/usr/bin/python2.7
+ARG PYTHON_EXECUTABLE=python
 ARG RUN_API_EXAMPLES
 ARG RUN_SYSTEM_TESTS
 ARG RUN_UNIT_TESTS