diff --git a/time/time.h b/time/time.h
index 486367f7dd..b6b439a452 100644
--- a/time/time.h
+++ b/time/time.h
@@ -76,8 +76,7 @@ extern clock_t clock (void) __THROW;
 extern time_t time (time_t *__timer) __THROW;
 
 /* Return the difference between TIME1 and TIME0.  */
-extern double difftime (time_t __time1, time_t __time0)
-     __THROW __attribute_pure__;
+extern double difftime (time_t __time1, time_t __time0);
 
 /* Return the `time_t' representation of TP and normalize TP.  */
 extern time_t mktime (struct tm *__tp) __THROW;
@@ -85,7 +84,7 @@ extern time_t mktime (struct tm *__tp) __THROW;
 # ifdef __REDIRECT_NTH
 extern time_t __REDIRECT_NTH (time, (time_t *__timer), __time64);
 extern double __REDIRECT_NTH (difftime, (time_t __time1, time_t __time0),
-                              __difftime64) __attribute_pure__;
+                              __difftime64);
 extern time_t __REDIRECT_NTH (mktime, (struct tm *__tp), __mktime64);
 # else
 #  define time __time64