diff --git a/racket/src/racket/src/schemef.h b/racket/src/racket/src/schemef.h
index ee71b73571..28d81790f3 100644
--- a/racket/src/racket/src/schemef.h
+++ b/racket/src/racket/src/schemef.h
@@ -198,7 +198,7 @@ MZ_EXTERN Scheme_On_Atomic_Timeout_Proc scheme_set_on_atomic_timeout(Scheme_On_A
 /*========================================================================*/
 
 MZ_EXTERN void scheme_signal_error(const char *msg, ...);
-MZ_EXTERN void scheme_raise_exn(int exnid, ...);
+MZ_EXTERN void scheme_raise_exn(int exnid, ...) __attribute__ ((noreturn));
 MZ_EXTERN void scheme_warning(char *msg, ...);
 
 MZ_EXTERN void scheme_raise(Scheme_Object *exn);
diff --git a/racket/src/racket/src/schemex.h b/racket/src/racket/src/schemex.h
index 21de876357..bd5a7a408c 100644
--- a/racket/src/racket/src/schemex.h
+++ b/racket/src/racket/src/schemex.h
@@ -139,7 +139,7 @@ Scheme_On_Atomic_Timeout_Proc (*scheme_set_on_atomic_timeout)(Scheme_On_Atomic_T
 /*                              error handling                            */
 /*========================================================================*/
 void (*scheme_signal_error)(const char *msg, ...);
-void (*scheme_raise_exn)(int exnid, ...);
+void (*scheme_raise_exn)(int exnid, ...) __attribute__ ((noreturn));
 void (*scheme_warning)(char *msg, ...);
 void (*scheme_raise)(Scheme_Object *exn);
 int (*scheme_log_level_p)(Scheme_Logger *logger, int level);