diff --git a/CHANGES b/CHANGES
index 2fd7265a88..748a42689d 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,5 @@
+5202.	[bug]		<dns/ecs.h> was missing ISC_LANG_ENDDECLS. [GL #976]
+
 5201.	[bug]		Fix a possible deadlock in RPZ update code. [GL #973]
 
 5198.	[bug]		If a fetch context was being shut down and, at the same
diff --git a/lib/dns/include/dns/ecs.h b/lib/dns/include/dns/ecs.h
index 42ab32056c..92cdda0dee 100644
--- a/lib/dns/include/dns/ecs.h
+++ b/lib/dns/include/dns/ecs.h
@@ -50,4 +50,6 @@ dns_ecs_format(dns_ecs_t *ecs, char *buf, size_t size);
  * \li  'size' is at least DNS_ECS_FORMATSIZE
  */
 
+ISC_LANG_ENDDECLS
+
 #endif /* DNS_ECS_H */