diff --git a/ChangeLog b/ChangeLog
index 8c072b668e..6d43ec83cc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2016-12-27  Florian Weimer  <fweimer@redhat.com>
+
+	[BZ #17252]
+	* posix/unistd.h (getentropy): Declare.
+
 2016-12-27  Florian Weimer  <fweimer@redhat.com>
 
 	* resolv/res_hconf.h (HCONF_FLAG_SPOOF, HCONF_FLAG_SPOOFALERT):
diff --git a/posix/unistd.h b/posix/unistd.h
index 392dc0e004..70b10c6a88 100644
--- a/posix/unistd.h
+++ b/posix/unistd.h
@@ -1157,6 +1157,11 @@ extern int pthread_atfork (void (*__prepare) (void),
 			   void (*__child) (void)) __THROW;
 #endif
 
+#ifdef __USE_GNU
+/* Write LENGTH bytes of randomness starting at BUFFER.  Return 0 on
+   success or -1 on error.  */
+int getentropy (void *__buffer, size_t __length) __wur;
+#endif
 
 /* Define some macros helping to catch buffer overflows.  */
 #if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function