diff --git a/asmrun/fail.c b/asmrun/fail.c
index 6b3e2fa2b..2b4b0eba4 100644
--- a/asmrun/fail.c
+++ b/asmrun/fail.c
@@ -33,13 +33,9 @@ typedef char caml_generated_constant[256];
 extern caml_generated_constant Out_of_memory, Sys_error, Failure,
   Invalid_argument, End_of_file, Division_by_zero, Not_found, Match_failure;
 
-/* Exception raising */
+/* Resetting the signal mask when raising an exception from C */
 
-extern void raise_caml_exception (value bucket) Noreturn;
-
-char * caml_exception_pointer = NULL;
-
-void mlraise(value v)
+static void default_reset_sigmask(void)
 {
 #ifdef POSIX_SIGNALS
   sigset_t mask;
@@ -50,6 +46,19 @@ void mlraise(value v)
   sigsetmask(0);
 #endif
 #endif
+}
+
+void (*caml_reset_sigmask)(void) = default_reset_sigmask;
+
+/* Exception raising */
+
+extern void raise_caml_exception (value bucket) Noreturn;
+
+char * caml_exception_pointer = NULL;
+
+void mlraise(value v)
+{
+  (*caml_reset_sigmask)();
   Unlock_exn();
   if (caml_exception_pointer == NULL) fatal_uncaught_exception(v);
 
diff --git a/byterun/fail.h b/byterun/fail.h
index e72bb03bc..302b83a6b 100644
--- a/byterun/fail.h
+++ b/byterun/fail.h
@@ -59,4 +59,6 @@ void raise_not_found (void) Noreturn;
 void fatal_uncaught_exception (value) Noreturn;
 void init_exceptions (void);
 
+extern void (*caml_reset_sigmask)(void);
+
 #endif /* _fail_ */
diff --git a/otherlibs/systhreads/posix.c b/otherlibs/systhreads/posix.c
index b53e7540c..b1df4a67a 100644
--- a/otherlibs/systhreads/posix.c
+++ b/otherlibs/systhreads/posix.c
@@ -225,6 +225,17 @@ static void caml_io_mutex_unlock_exn(void)
   if (chan != NULL) caml_io_mutex_unlock(chan);
 }
 
+/* Hook for resetting signals in mlraise() (in native-code only) */
+
+#ifdef NATIVE_CODE
+static void caml_thread_reset_sigmask(void)
+{
+  sigset_t mask;
+  sigemptyset(&mask);
+  pthread_sigmask(SIG_SETMASK, &mask, NULL);
+}
+#endif
+
 /* The "tick" thread fakes a SIGVTALRM signal at regular intervals. */
 
 static void * caml_thread_tick(void * arg)
@@ -301,6 +312,9 @@ value caml_thread_initialize(value unit)   /* ML */
     channel_mutex_lock = caml_io_mutex_lock;
     channel_mutex_unlock = caml_io_mutex_unlock;
     channel_mutex_unlock_exn = caml_io_mutex_unlock_exn;
+#ifdef NATIVE_CODE
+    caml_reset_sigmask = caml_thread_reset_sigmask;
+#endif
     /* Fork the tick thread */
     pthread_attr_init(&attr);
     pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);