diff --git a/CHANGES b/CHANGES
index cc3cc97e4e..5535b49815 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,6 @@
+2318.	[port]		ISC_PLATFORM_NEEDTIMESPEC missing from
+			lib/bind/config.h.in. [RT #17514]
+
 2317.	[bug]		"make distclean" removed bind9.xsl.h. [RT #17518]
 
 2316.	[port]		Missing #include <isc/print.h> in lib/dns/gssapictx.c.
diff --git a/lib/bind/config.h.in b/lib/bind/config.h.in
index 69ea285430..97b79a4d3b 100644
--- a/lib/bind/config.h.in
+++ b/lib/bind/config.h.in
@@ -13,6 +13,7 @@
 #undef POSIX_GETGRNAM_R
 #undef HAVE_MEMMOVE
 #undef HAVE_MEMCHR
+#undef ISC_PLATFORM_NEEDTIMESPEC
 
 #undef NEED_SETGROUPENT
 #undef NEED_GETGROUPLIST