diff --git a/test/std/numerics/numeric.ops/numeric.ops.gcd/gcd.pass.cpp b/test/std/numerics/numeric.ops/numeric.ops.gcd/gcd.pass.cpp
index ddb14cd34..0774bff40 100644
--- a/test/std/numerics/numeric.ops/numeric.ops.gcd/gcd.pass.cpp
+++ b/test/std/numerics/numeric.ops/numeric.ops.gcd/gcd.pass.cpp
@@ -8,6 +8,8 @@
 //===----------------------------------------------------------------------===//
 //
 // UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: ubsan
+
 // <numeric>
 
 // template<class _M, class _N>
diff --git a/test/std/numerics/numeric.ops/numeric.ops.lcm/lcm.pass.cpp b/test/std/numerics/numeric.ops/numeric.ops.lcm/lcm.pass.cpp
index 799a7ebfa..a74ac76a3 100644
--- a/test/std/numerics/numeric.ops/numeric.ops.lcm/lcm.pass.cpp
+++ b/test/std/numerics/numeric.ops/numeric.ops.lcm/lcm.pass.cpp
@@ -8,6 +8,7 @@
 //===----------------------------------------------------------------------===//
 //
 // UNSUPPORTED: c++98, c++03, c++11, c++14
+// XFAIL: ubsan
 // <numeric>
 
 // template<class _M, class _N>