diff --git a/src/backend/executor/execPartition.c b/src/backend/executor/execPartition.c
index dac789d414..b5f796f5ed 100644
--- a/src/backend/executor/execPartition.c
+++ b/src/backend/executor/execPartition.c
@@ -1669,6 +1669,19 @@ ExecFindInitialMatchingSubPlans(PartitionPruneState *prunestate, int nsubplans)
 				new_subplan_indexes[i] = newidx++;
 			else
 				new_subplan_indexes[i] = -1;	/* Newly pruned */
+
+			/*
+			 * If a subplan in other_subplans got its index updated, update
+			 * other_subplans too.
+			 */
+			if (bms_is_member(i, prunestate->other_subplans))
+			{
+				prunestate->other_subplans =
+							bms_del_member(prunestate->other_subplans, i);
+				prunestate->other_subplans =
+							bms_add_member(prunestate->other_subplans,
+										   new_subplan_indexes[i]);
+			}
 		}
 
 		/*