diff --git a/CHANGES b/CHANGES
index 178d285af7..d2cfb925d3 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,6 @@
+4343.	[bug]		dns_dnssec_syncupdate misdeclared in <dns/dnssec.h>.
+			[RT #42090]
+
 4342.	[bug]		'rndc flushtree' could fail to clean the tree if there
 			wasn't a node at the specified name. [RT #41846]
 
diff --git a/lib/dns/include/dns/dnssec.h b/lib/dns/include/dns/dnssec.h
index 59bc7c1632..81960fd4a1 100644
--- a/lib/dns/include/dns/dnssec.h
+++ b/lib/dns/include/dns/dnssec.h
@@ -374,7 +374,7 @@ dns_dnssec_updatekeys(dns_dnsseckeylist_t *keys, dns_dnsseckeylist_t *newkeys,
  * On completion, any remaining keys in 'newkeys' are freed.
  */
 
-isc_boolean_t
+isc_result_t
 dns_dnssec_syncupdate(dns_dnsseckeylist_t *keys, dns_dnsseckeylist_t *rmkeys,
 		      dns_rdataset_t *cds, dns_rdataset_t *cdnskey,
 		      isc_stdtime_t now, dns_ttl_t hint_ttl, dns_diff_t *diff,