diff --git a/include/setjmp.h b/include/setjmp.h
index 73fe01c..e9038e6 100644
--- a/include/setjmp.h
+++ b/include/setjmp.h
@@ -9,12 +9,14 @@
 typedef struct __jmp_buf jmp_buf[1];
 
 /* Save the calling environment in __env (not the signal mask), return 0. */
+__attribute__((returns_twice))
 extern int setjmp(jmp_buf __env);
 
 /* Standard requires setjmp to be a macro (7.13§1) */
 #define setjmp setjmp
 
 /* Restore the calling environment from __env, return __val to setjmp. */
+__attribute__((noreturn))
 extern void longjmp(jmp_buf __env, int __val);
 
 #endif /*__SETJMP_H__*/
diff --git a/include/stdlib.h b/include/stdlib.h
index 5f68ab0..5b54c43 100644
--- a/include/stdlib.h
+++ b/include/stdlib.h
@@ -31,12 +31,15 @@ extern void free(void *__ptr);
 /* Communication with the environment. */
 
 /* Abort execution; raises SIGABRT and leaves quickly with _Exit(). */
+__attribute__((noreturn))
 void abort(void);
 
 /* Exit; calls handlers, flushes and closes streams and temporary files. */
+__attribute__((noreturn))
 void exit(int __status);
 
 /* Exit immediately, bypassing exit handlers or signal handlers. */
+__attribute__((noreturn))
 void _Exit(int __status);
 
 /* Integer arithmetic functions. */