diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.cpp b/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.cpp
--- a/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.cpp
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_platform_limits_posix.cpp
@@ -217,7 +217,7 @@
   unsigned struct_sockaddr_sz = sizeof(struct sockaddr);
 
   unsigned ucontext_t_sz(void *ctx) {
-#    if SANITIZER_GLIBC && SANITIZER_X64
+#    if SANITIZER_GLIBC && SANITIZER_X64 &&  __GLIBC_PREREQ (2, 27)
     // See kernel arch/x86/kernel/fpu/signal.c for details.
     const auto *fpregs = static_cast<ucontext_t *>(ctx)->uc_mcontext.fpregs;
     // The member names differ across header versions, but the actual layout
diff --git a/compiler-rt/test/msan/Linux/signal_mcontext.cpp b/compiler-rt/test/msan/Linux/signal_mcontext.cpp
--- a/compiler-rt/test/msan/Linux/signal_mcontext.cpp
+++ b/compiler-rt/test/msan/Linux/signal_mcontext.cpp
@@ -10,7 +10,7 @@
 
 void handler(int sig, siginfo_t *info, void *uctx) {
   __msan_check_mem_is_initialized(uctx, sizeof(ucontext_t));
-#if defined(__GLIBC__) && defined(__x86_64__)
+#if defined(__GLIBC__) && defined(__x86_64__) && __GLIBC_PREREQ(2, 27)
   auto *mctx = &static_cast<ucontext_t *>(uctx)->uc_mcontext;
   if (auto *fpregs = mctx->fpregs) {
     // The member names differ across header versions, but the actual layout