diff --git a/compiler-rt/lib/msan/msan_thread.h b/compiler-rt/lib/msan/msan_thread.h
--- a/compiler-rt/lib/msan/msan_thread.h
+++ b/compiler-rt/lib/msan/msan_thread.h
@@ -15,7 +15,7 @@
 
 #include "msan_allocator.h"
 #include "sanitizer_common/sanitizer_common.h"
-
+#include "sanitizer_common/sanitizer_posix.h"
 namespace __msan {
 
 class MsanThread {
@@ -69,6 +69,8 @@
 
   unsigned in_signal_handler_;
 
+  __sanitizer_sigset_t sigset_;
+
   MsanThreadLocalMallocStorage malloc_storage_;
 };
 
diff --git a/compiler-rt/lib/msan/msan_thread.cpp b/compiler-rt/lib/msan/msan_thread.cpp
--- a/compiler-rt/lib/msan/msan_thread.cpp
+++ b/compiler-rt/lib/msan/msan_thread.cpp
@@ -1,8 +1,12 @@
 
-#include "msan.h"
 #include "msan_thread.h"
-#include "msan_interface_internal.h"
 
+#include <signal.h>
+
+#include "msan.h"
+#include "msan_interface_internal.h"
+#include "sanitizer_common/sanitizer_linux.h"
+#include "sanitizer_common/sanitizer_posix.h"
 #include "sanitizer_common/sanitizer_tls_get_addr.h"
 
 namespace __msan {
@@ -16,6 +20,10 @@
   thread->arg_ = arg;
   thread->destructor_iterations_ = GetPthreadDestructorIterations();
 
+  __sanitizer_sigset_t set;
+  internal_sigfillset(&set);
+  CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &set, &thread->sigset_));
+
   return thread;
 }
 
@@ -47,6 +55,8 @@
   CHECK(MEM_IS_APP(stack_.bottom));
   CHECK(MEM_IS_APP(stack_.top - 1));
   ClearShadowForThreadStackAndTLS();
+
+  CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &sigset_, nullptr));
 }
 
 void MsanThread::TSDDtor(void *tsd) {