diff --git a/doc/Changelog b/doc/Changelog
index 90a25be0b..a7f4af702 100644
--- a/doc/Changelog
+++ b/doc/Changelog
@@ -1,6 +1,8 @@
 26 November 2018: Wouter
 	- Fix to not set GLOB_NOSORT so the unbound.conf include: files are
 	  sorted and in a predictable order.
+	- Fix #4193: Fix that prefetch failure does not overwrite valid cache
+	  entry with SERVFAIL.
 
 22 November 2018: Wouter
 	- With ./configure --with-pyunbound --with-pythonmodule
diff --git a/iterator/iterator.c b/iterator/iterator.c
index e177dcf1f..ee970975a 100644
--- a/iterator/iterator.c
+++ b/iterator/iterator.c
@@ -292,7 +292,7 @@ error_response_cache(struct module_qstate* qstate, int id, int rcode)
 	if(!qstate->no_cache_store) {
 		/* store in cache */
 		struct reply_info err;
-		if(qstate->prefetch_leeway > NORR_TTL) {
+		if(qstate->prefetch_leeway > 0) {
 			verbose(VERB_ALGO, "error response for prefetch in cache");
 			/* attempt to adjust the cache entry prefetch */
 			if(dns_cache_prefetch_adjust(qstate->env, &qstate->qinfo,