diff --git a/src/test/regress/expected/join_hash.out b/src/test/regress/expected/join_hash.out
index 75009e29720..a4689363200 100644
--- a/src/test/regress/expected/join_hash.out
+++ b/src/test/regress/expected/join_hash.out
@@ -49,6 +49,23 @@ begin
   end loop;
 end;
 $$;
+create or replace function hash_actual_rows(query text)
+returns int language plpgsql
+as
+$$
+declare
+  whole_plan json;
+  hash_node json;
+begin
+  for whole_plan in
+    execute 'explain (analyze, format ''json'') ' || query
+  loop
+    hash_node := find_hash(json_extract_path(whole_plan, '0', 'Plan'));
+    return (hash_node->>'Actual Rows')::float::int;
+  end loop;
+  return null;
+end;
+$$;
 -- Make a simple relation with well distributed keys and correctly
 -- estimated size.
 create table simple as
@@ -312,6 +329,18 @@ select count(*) from simple r full outer join simple s using (id);
  20002
 (1 row)
 
+-- Hash node's rowcount should include null-key rows that are kept for full join
+savepoint settings;
+set local max_parallel_workers_per_gather = 0;
+set local enable_parallel_hash = off;
+select hash_actual_rows($$
+  select count(*) from simple r full outer join simple s using (id);
+$$);
+ hash_actual_rows 
+------------------
+            20001
+(1 row)
+
 rollback to settings;
 -- The "bad" case: during execution we need to increase number of
 -- batches; in this case we plan for 1 batch, and increase at least a
diff --git a/src/test/regress/sql/join_hash.sql b/src/test/regress/sql/join_hash.sql
index 989390e6864..4b951310b4e 100644
--- a/src/test/regress/sql/join_hash.sql
+++ b/src/test/regress/sql/join_hash.sql
@@ -53,6 +53,24 @@ begin
 end;
 $$;
 
+create or replace function hash_actual_rows(query text)
+returns int language plpgsql
+as
+$$
+declare
+  whole_plan json;
+  hash_node json;
+begin
+  for whole_plan in
+    execute 'explain (analyze, format ''json'') ' || query
+  loop
+    hash_node := find_hash(json_extract_path(whole_plan, '0', 'Plan'));
+    return (hash_node->>'Actual Rows')::float::int;
+  end loop;
+  return null;
+end;
+$$;
+
 -- Make a simple relation with well distributed keys and correctly
 -- estimated size.
 create table simple as
@@ -190,6 +208,14 @@ $$
 $$);
 -- parallel full multi-batch hash join
 select count(*) from simple r full outer join simple s using (id);
+
+-- Hash node's rowcount should include null-key rows that are kept for full join
+savepoint settings;
+set local max_parallel_workers_per_gather = 0;
+set local enable_parallel_hash = off;
+select hash_actual_rows($$
+  select count(*) from simple r full outer join simple s using (id);
+$$);
 rollback to settings;
 
 -- The "bad" case: during execution we need to increase number of