diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index 1ea6b84561..d5ae9469a1 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -1204,7 +1204,7 @@ _copyPartitionedRelPruneInfo(const PartitionedRelPruneInfo *from)
 	COPY_SCALAR_FIELD(nexprs);
 	COPY_POINTER_FIELD(subplan_map, from->nparts * sizeof(int));
 	COPY_POINTER_FIELD(subpart_map, from->nparts * sizeof(int));
-	COPY_POINTER_FIELD(relid_map, from->nparts * sizeof(int));
+	COPY_POINTER_FIELD(relid_map, from->nparts * sizeof(Oid));
 	COPY_POINTER_FIELD(hasexecparam, from->nexprs * sizeof(bool));
 	COPY_SCALAR_FIELD(do_initial_prune);
 	COPY_SCALAR_FIELD(do_exec_prune);
diff --git a/src/backend/partitioning/partprune.c b/src/backend/partitioning/partprune.c
index 31e0164ea9..6d67c428fe 100644
--- a/src/backend/partitioning/partprune.c
+++ b/src/backend/partitioning/partprune.c
@@ -436,7 +436,7 @@ make_partitionedrel_pruneinfo(PlannerInfo *root, RelOptInfo *parentrel,
 		 */
 		subplan_map = (int *) palloc(nparts * sizeof(int));
 		subpart_map = (int *) palloc(nparts * sizeof(int));
-		relid_map = (Oid *) palloc(nparts * sizeof(int));
+		relid_map = (Oid *) palloc(nparts * sizeof(Oid));
 		present_parts = NULL;
 
 		for (i = 0; i < nparts; i++)