diff --git a/lib/dns/dst_api.c b/lib/dns/dst_api.c
index ca81410089..803214c096 100644
--- a/lib/dns/dst_api.c
+++ b/lib/dns/dst_api.c
@@ -691,6 +691,10 @@ dst_key_fromnamedfile(const char *filename, const char *dirname, int type,
 	}
 
 	key->modified = false;
+
+	if (dirname != NULL) {
+		key->directory = isc_mem_strdup(mctx, dirname);
+	}
 	*keyp = key;
 	key = NULL;
 
@@ -1395,6 +1399,9 @@ dst_key_free(dst_key_t **keyp) {
 			INSIST(key->func->destroy != NULL);
 			key->func->destroy(key);
 		}
+		if (key->directory != NULL) {
+			isc_mem_free(mctx, key->directory);
+		}
 		if (key->engine != NULL) {
 			isc_mem_free(mctx, key->engine);
 		}
diff --git a/lib/dns/dst_internal.h b/lib/dns/dst_internal.h
index a4fcc05bd8..7026e7ffae 100644
--- a/lib/dns/dst_internal.h
+++ b/lib/dns/dst_internal.h
@@ -91,6 +91,7 @@ struct dst_key {
 	dns_rdataclass_t key_class; /*%< class of the key record */
 	dns_ttl_t key_ttl;	    /*%< default/initial dnskey ttl */
 	isc_mem_t *mctx;	    /*%< memory context */
+	char *directory;	    /*%< key directory */
 	char *engine;		    /*%< engine name (HSM) */
 	char *label;		    /*%< engine label (HSM) */
 	char *object;		    /*%< engine object (HSM) */