diff --git a/src/backend/executor/nodeSubplan.c b/src/backend/executor/nodeSubplan.c
index d615b78373..b501fc4f03 100644
--- a/src/backend/executor/nodeSubplan.c
+++ b/src/backend/executor/nodeSubplan.c
@@ -46,7 +46,8 @@ static Datum ExecScanSubPlan(SubPlanState *node,
 				ExprContext *econtext,
 				bool *isNull);
 static void buildSubPlanHash(SubPlanState *node, ExprContext *econtext);
-static bool findPartialMatch(TupleHashTable hashtable, TupleTableSlot *slot);
+static bool findPartialMatch(TupleHashTable hashtable, TupleTableSlot *slot,
+				 FmgrInfo *eqfunctions);
 static bool slotAllNulls(TupleTableSlot *slot);
 static bool slotNoNulls(TupleTableSlot *slot);
 
@@ -153,7 +154,7 @@ ExecHashSubPlan(SubPlanState *node,
 			return BoolGetDatum(true);
 		}
 		if (node->havenullrows &&
-			findPartialMatch(node->hashnulls, slot))
+			findPartialMatch(node->hashnulls, slot, node->cur_eq_funcs))
 		{
 			ExecClearTuple(slot);
 			*isNull = true;
@@ -186,14 +187,14 @@ ExecHashSubPlan(SubPlanState *node,
 	}
 	/* Scan partly-null table first, since more likely to get a match */
 	if (node->havenullrows &&
-		findPartialMatch(node->hashnulls, slot))
+		findPartialMatch(node->hashnulls, slot, node->cur_eq_funcs))
 	{
 		ExecClearTuple(slot);
 		*isNull = true;
 		return BoolGetDatum(false);
 	}
 	if (node->havehashrows &&
-		findPartialMatch(node->hashtable, slot))
+		findPartialMatch(node->hashtable, slot, node->cur_eq_funcs))
 	{
 		ExecClearTuple(slot);
 		*isNull = true;
@@ -573,9 +574,13 @@ buildSubPlanHash(SubPlanState *node, ExprContext *econtext)
  * We have to scan the whole hashtable; we can't usefully use hashkeys
  * to guide probing, since we might get partial matches on tuples with
  * hashkeys quite unrelated to what we'd get from the given tuple.
+ *
+ * Caller must provide the equality functions to use, since in cross-type
+ * cases these are different from the hashtable's internal functions.
  */
 static bool
-findPartialMatch(TupleHashTable hashtable, TupleTableSlot *slot)
+findPartialMatch(TupleHashTable hashtable, TupleTableSlot *slot,
+				 FmgrInfo *eqfunctions)
 {
 	int			numCols = hashtable->numCols;
 	AttrNumber *keyColIdx = hashtable->keyColIdx;
@@ -588,7 +593,7 @@ findPartialMatch(TupleHashTable hashtable, TupleTableSlot *slot)
 		ExecStoreMinimalTuple(entry->firstTuple, hashtable->tableslot, false);
 		if (!execTuplesUnequal(slot, hashtable->tableslot,
 							   numCols, keyColIdx,
-							   hashtable->cur_eq_funcs,
+							   eqfunctions,
 							   hashtable->tempcxt))
 		{
 			TermTupleHashIterator(&hashiter);
diff --git a/src/test/regress/expected/subselect.out b/src/test/regress/expected/subselect.out
index 30cff04cb7..6a81df9538 100644
--- a/src/test/regress/expected/subselect.out
+++ b/src/test/regress/expected/subselect.out
@@ -543,6 +543,23 @@ from
 -----
 (0 rows)
 
+--
+-- Test case for cross-type partial matching in hashed subplan (bug #7597)
+--
+create temp table outer_7597 (f1 int4, f2 int4);
+insert into outer_7597 values (0, 0);
+insert into outer_7597 values (1, 0);
+insert into outer_7597 values (0, null);
+insert into outer_7597 values (1, null);
+create temp table inner_7597(c1 int8, c2 int8);
+insert into inner_7597 values(0, null);
+select * from outer_7597 where (f1, f2) not in (select * from inner_7597);
+ f1 | f2 
+----+----
+  1 |  0
+  1 |   
+(2 rows)
+
 --
 -- Test case for premature memory release during hashing of subplan output
 --
diff --git a/src/test/regress/sql/subselect.sql b/src/test/regress/sql/subselect.sql
index e07a30ed03..cba449a203 100644
--- a/src/test/regress/sql/subselect.sql
+++ b/src/test/regress/sql/subselect.sql
@@ -345,6 +345,21 @@ from
   join
   int4_tbl i4 on dummy = i4.f1;
 
+--
+-- Test case for cross-type partial matching in hashed subplan (bug #7597)
+--
+
+create temp table outer_7597 (f1 int4, f2 int4);
+insert into outer_7597 values (0, 0);
+insert into outer_7597 values (1, 0);
+insert into outer_7597 values (0, null);
+insert into outer_7597 values (1, null);
+
+create temp table inner_7597(c1 int8, c2 int8);
+insert into inner_7597 values(0, null);
+
+select * from outer_7597 where (f1, f2) not in (select * from inner_7597);
+
 --
 -- Test case for premature memory release during hashing of subplan output
 --