diff --git a/compiler-rt/lib/msan/tests/CMakeLists.txt b/compiler-rt/lib/msan/tests/CMakeLists.txt
index a8500225337e6..26a86afd4674f 100644
--- a/compiler-rt/lib/msan/tests/CMakeLists.txt
+++ b/compiler-rt/lib/msan/tests/CMakeLists.txt
@@ -63,6 +63,9 @@ set(MSAN_UNITTEST_LINK_FLAGS
   # inputs.
 )
 
+append_list_if(CMAKE_SYSROOT "--sysroot=${CMAKE_SYSROOT}" MSAN_UNITTEST_COMMON_CFLAGS)
+append_list_if(CMAKE_SYSROOT "--sysroot=${CMAKE_SYSROOT}" MSAN_UNITTEST_LINK_FLAGS)
+
 append_list_if(COMPILER_RT_HAS_LIBDL -ldl MSAN_UNITTEST_LINK_FLAGS)
 
 macro(msan_compile obj_list source arch kind cflags)
diff --git a/compiler-rt/test/msan/lit.cfg.py b/compiler-rt/test/msan/lit.cfg.py
index 361be79e2557e..bcc6d693022ee 100644
--- a/compiler-rt/test/msan/lit.cfg.py
+++ b/compiler-rt/test/msan/lit.cfg.py
@@ -19,6 +19,8 @@
     + [config.target_cflags]
     + config.debug_info_flags
 )
+if config.cmake_sysroot:
+    clang_msan_cflags += [f"--sysroot={config.cmake_sysroot}"]
 # Some Msan tests leverage backtrace() which requires libexecinfo on FreeBSD.
 if config.host_os == "FreeBSD":
     clang_msan_cflags += ["-lexecinfo", "-fPIC"]
diff --git a/compiler-rt/test/msan/lit.site.cfg.py.in b/compiler-rt/test/msan/lit.site.cfg.py.in
index 47264d0986946..41231359692ed 100644
--- a/compiler-rt/test/msan/lit.site.cfg.py.in
+++ b/compiler-rt/test/msan/lit.site.cfg.py.in
@@ -6,6 +6,7 @@ config.target_cflags = "@MSAN_TEST_TARGET_CFLAGS@"
 config.target_arch = "@MSAN_TEST_TARGET_ARCH@"
 config.use_lld = @MSAN_TEST_USE_LLD@
 config.use_thinlto = @MSAN_TEST_USE_THINLTO@
+config.cmake_sysroot = "@CMAKE_SYSROOT@"
 
 # Load common config for all compiler-rt lit tests.
 lit_config.load_config(config, "@COMPILER_RT_BINARY_DIR@/test/lit.common.configured")