diff --git a/doc/Changelog b/doc/Changelog
index 3b9845c4d..6100d9a04 100644
--- a/doc/Changelog
+++ b/doc/Changelog
@@ -1,5 +1,7 @@
 29 July 2019: Wouter
 	- Add verbose log message when auth zone file is written, at level 4.
+	- Add hex print of trust anchor pointer to trust anchor file temp
+	  name to make it unique, for libunbound created multiple contexts.
 
 23 July 2019: Wouter
 	- Fix question section mismatch in local zone redirect.
diff --git a/validator/autotrust.c b/validator/autotrust.c
index a72967302..dceb2dcf5 100644
--- a/validator/autotrust.c
+++ b/validator/autotrust.c
@@ -1182,8 +1182,8 @@ void autr_write_file(struct module_env* env, struct trust_anchor* tp)
 		return;
 	}
 	/* unique name with pid number and thread number */
-	snprintf(tempf, sizeof(tempf), "%s.%d-%d", fname, (int)getpid(),
-		env->worker?*(int*)env->worker:0);
+	snprintf(tempf, sizeof(tempf), "%s.%d-%d-%llx", fname, (int)getpid(),
+		env->worker?*(int*)env->worker:0, (long long int)tp);
 	verbose(VERB_ALGO, "autotrust: write to disk: %s", tempf);
 	out = fopen(tempf, "w");
 	if(!out) {