diff --git a/compiler-rt/test/asan/TestCases/Linux/odr-vtable.cpp b/compiler-rt/test/asan/TestCases/Linux/odr-vtable.cpp
--- a/compiler-rt/test/asan/TestCases/Linux/odr-vtable.cpp
+++ b/compiler-rt/test/asan/TestCases/Linux/odr-vtable.cpp
@@ -2,18 +2,18 @@
 // XFAIL: !compiler-rt-optimized && !riscv64
 
 /// Not using private alias or enabling ODR indicator can detect ODR issues.
-// RUN: %clangxx_asan -fno-rtti -DBUILD_SO1 -fPIC -shared -mllvm -asan-use-private-alias=0 %s -o %dynamiclib1
-// RUN: %clangxx_asan -fno-rtti -DBUILD_SO2 -fPIC -shared -mllvm -asan-use-private-alias=0 %s -o %dynamiclib2
-// RUN: %clangxx_asan -fno-rtti %s %ld_flags_rpath_exe1 %ld_flags_rpath_exe2 -o %t
+// RUN: %clangxx_asan -fno-rtti -DBUILD_SO1 -fPIC -shared -mllvm -asan-use-private-alias=0 %s -o %dynamiclib1 -Wl,--undefined=__cxa_demangle
+// RUN: %clangxx_asan -fno-rtti -DBUILD_SO2 -fPIC -shared -mllvm -asan-use-private-alias=0 %s -o %dynamiclib2 -Wl,--undefined=__cxa_demangle
+// RUN: %clangxx_asan -fno-rtti %s %ld_flags_rpath_exe1 %ld_flags_rpath_exe2 -o %t -Wl,--undefined=__cxa_demangle
 // RUN: %env_asan_opts=fast_unwind_on_malloc=0:detect_odr_violation=2 not %run %t 2>&1 | FileCheck %s
 
-// RUN: %clangxx_asan -fno-rtti -DBUILD_SO1 -fPIC -shared -mllvm -asan-use-odr-indicator=1 %s -o %dynamiclib1
-// RUN: %clangxx_asan -fno-rtti -DBUILD_SO2 -fPIC -shared -mllvm -asan-use-odr-indicator=1 %s -o %dynamiclib2
+// RUN: %clangxx_asan -fno-rtti -DBUILD_SO1 -fPIC -shared -mllvm -asan-use-odr-indicator=1 %s -o %dynamiclib1 -Wl,--undefined=__cxa_demangle
+// RUN: %clangxx_asan -fno-rtti -DBUILD_SO2 -fPIC -shared -mllvm -asan-use-odr-indicator=1 %s -o %dynamiclib2 -Wl,--undefined=__cxa_demangle
 // RUN: %env_asan_opts=fast_unwind_on_malloc=0:detect_odr_violation=2 not %run %t 2>&1 | FileCheck %s
 
 /// By default we can detect ODR issues in vtables.
-// RUN: %clangxx_asan -fno-rtti -DBUILD_SO1 -fPIC -shared %s -o %dynamiclib1
-// RUN: %clangxx_asan -fno-rtti -DBUILD_SO2 -fPIC -shared %s -o %dynamiclib2
+// RUN: %clangxx_asan -fno-rtti -DBUILD_SO1 -fPIC -shared %s -o %dynamiclib1 -Wl,--undefined=__cxa_demangle
+// RUN: %clangxx_asan -fno-rtti -DBUILD_SO2 -fPIC -shared %s -o %dynamiclib2 -Wl,--undefined=__cxa_demangle
 // RUN: %env_asan_opts=fast_unwind_on_malloc=0:detect_odr_violation=2 not %run %t 2>&1 | FileCheck %s
 
 struct XYZ {
diff --git a/compiler-rt/test/ubsan/TestCases/TypeCheck/vptr-virtual-base.cpp b/compiler-rt/test/ubsan/TestCases/TypeCheck/vptr-virtual-base.cpp
--- a/compiler-rt/test/ubsan/TestCases/TypeCheck/vptr-virtual-base.cpp
+++ b/compiler-rt/test/ubsan/TestCases/TypeCheck/vptr-virtual-base.cpp
@@ -1,4 +1,4 @@
-// RUN: %clangxx -frtti -fsanitize=null,vptr -fno-sanitize-recover=vptr -g %s -O3 -o %t
+// RUN: %clangxx -frtti -fsanitize=null,vptr -fno-sanitize-recover=vptr -Wl,--undefined=__cxa_demangle -g %s -O3 -o %t
 // RUN: not %run %t 2>&1 | FileCheck %s
 
 // REQUIRES: cxxabi