diff --git a/src/resolve/resolved-dns-scope.c b/src/resolve/resolved-dns-scope.c
index 6b496af412..fc4ae57ce0 100644
--- a/src/resolve/resolved-dns-scope.c
+++ b/src/resolve/resolved-dns-scope.c
@@ -70,11 +70,11 @@ int dns_scope_new(Manager *m, DnsScope **ret, Link *l, DnsProtocol protocol, int
 }
 
 static void dns_scope_abort_transactions(DnsScope *s) {
-        DnsTransaction *t;
-
         assert(s);
 
-        while ((t = hashmap_first(s->transactions))) {
+        while (s->transactions) {
+                DnsTransaction *t = s->transactions;
+
                 /* Abort the transaction, but make sure it is not
                  * freed while we still look at it */
 
@@ -100,7 +100,7 @@ DnsScope* dns_scope_free(DnsScope *s) {
         while (s->query_candidates)
                 dns_query_candidate_free(s->query_candidates);
 
-        hashmap_free(s->transactions);
+        hashmap_free(s->transactions_by_key);
 
         while ((rr = ordered_hashmap_steal_first(s->conflict_queue)))
                 dns_resource_record_unref(rr);
@@ -653,7 +653,7 @@ DnsTransaction *dns_scope_find_transaction(DnsScope *scope, DnsResourceKey *key,
 
         /* Try to find an ongoing transaction that is a equal to the
          * specified question */
-        t = hashmap_get(scope->transactions, key);
+        t = hashmap_get(scope->transactions_by_key, key);
         if (!t)
                 return NULL;
 
diff --git a/src/resolve/resolved-dns-scope.h b/src/resolve/resolved-dns-scope.h
index 32e6961757..7876410b7d 100644
--- a/src/resolve/resolved-dns-scope.h
+++ b/src/resolve/resolved-dns-scope.h
@@ -58,9 +58,19 @@ struct DnsScope {
         usec_t resend_timeout;
         usec_t max_rtt;
 
-        Hashmap *transactions;
         LIST_HEAD(DnsQueryCandidate, query_candidates);
 
+        /* Note that we keep track of ongoing transactions in two
+         * ways: once in a hashmap, indexed by the rr key, and once in
+         * a linked list. We use the hashmap to quickly find
+         * transactions we can reuse for a key. But note that there
+         * might be multiple transactions for the same key (because
+         * the zone probing can't reuse a transaction answered from
+         * the zone or the cache), and the hashmap only tracks the
+         * most recent entry. */
+        Hashmap *transactions_by_key;
+        LIST_HEAD(DnsTransaction, transactions);
+
         LIST_FIELDS(DnsScope, scopes);
 };
 
diff --git a/src/resolve/resolved-dns-transaction.c b/src/resolve/resolved-dns-transaction.c
index 519358ffb1..c65c9c9f49 100644
--- a/src/resolve/resolved-dns-transaction.c
+++ b/src/resolve/resolved-dns-transaction.c
@@ -49,7 +49,8 @@ DnsTransaction* dns_transaction_free(DnsTransaction *t) {
         dns_stream_free(t->stream);
 
         if (t->scope) {
-                hashmap_remove(t->scope->transactions, t->key);
+                hashmap_remove_value(t->scope->transactions_by_key, t->key, t);
+                LIST_REMOVE(transactions_by_scope, t->scope->transactions, t);
 
                 if (t->id != 0)
                         hashmap_remove(t->scope->manager->dns_transactions, UINT_TO_PTR(t->id));
@@ -94,7 +95,7 @@ int dns_transaction_new(DnsTransaction **ret, DnsScope *s, DnsResourceKey *key)
         if (r < 0)
                 return r;
 
-        r = hashmap_ensure_allocated(&s->transactions, &dns_resource_key_hash_ops);
+        r = hashmap_ensure_allocated(&s->transactions_by_key, &dns_resource_key_hash_ops);
         if (r < 0)
                 return r;
 
@@ -118,12 +119,13 @@ int dns_transaction_new(DnsTransaction **ret, DnsScope *s, DnsResourceKey *key)
                 return r;
         }
 
-        r = hashmap_put(s->transactions, t->key, t);
+        r = hashmap_replace(s->transactions_by_key, t->key, t);
         if (r < 0) {
                 hashmap_remove(s->manager->dns_transactions, UINT_TO_PTR(t->id));
                 return r;
         }
 
+        LIST_PREPEND(transactions_by_scope, s->transactions, t);
         t->scope = s;
 
         if (ret)