diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index 65bbc18ecb..d666e860da 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -96,6 +96,7 @@ _copyPlannedStmt(const PlannedStmt *from)
 	COPY_BITMAPSET_FIELD(rewindPlanIDs);
 	COPY_NODE_FIELD(rowMarks);
 	COPY_NODE_FIELD(relationOids);
+	COPY_NODE_FIELD(partitionOids);
 	COPY_NODE_FIELD(invalItems);
 	COPY_NODE_FIELD(paramExecTypes);
 	COPY_NODE_FIELD(utilityStmt);
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index f5dcedf6e8..5c2cdc697b 100644
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -314,6 +314,7 @@ _outPlannedStmt(StringInfo str, const PlannedStmt *node)
 	WRITE_BITMAPSET_FIELD(rewindPlanIDs);
 	WRITE_NODE_FIELD(rowMarks);
 	WRITE_NODE_FIELD(relationOids);
+	WRITE_NODE_FIELD(partitionOids);
 	WRITE_NODE_FIELD(invalItems);
 	WRITE_NODE_FIELD(paramExecTypes);
 	WRITE_NODE_FIELD(utilityStmt);
@@ -2211,6 +2212,7 @@ _outPlannerGlobal(StringInfo str, const PlannerGlobal *node)
 	WRITE_NODE_FIELD(resultRelations);
 	WRITE_NODE_FIELD(appendRelations);
 	WRITE_NODE_FIELD(relationOids);
+	WRITE_NODE_FIELD(partitionOids);
 	WRITE_NODE_FIELD(invalItems);
 	WRITE_NODE_FIELD(paramExecTypes);
 	WRITE_UINT_FIELD(lastPHId);
diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c
index 4388aae71d..8962b37e2d 100644
--- a/src/backend/nodes/readfuncs.c
+++ b/src/backend/nodes/readfuncs.c
@@ -1590,6 +1590,7 @@ _readPlannedStmt(void)
 	READ_BITMAPSET_FIELD(rewindPlanIDs);
 	READ_NODE_FIELD(rowMarks);
 	READ_NODE_FIELD(relationOids);
+	READ_NODE_FIELD(partitionOids);
 	READ_NODE_FIELD(invalItems);
 	READ_NODE_FIELD(paramExecTypes);
 	READ_NODE_FIELD(utilityStmt);
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index 18610c2345..85659acd75 100644
--- a/src/backend/optimizer/plan/planner.c
+++ b/src/backend/optimizer/plan/planner.c
@@ -527,6 +527,9 @@ standard_planner(Query *parse, const char *query_string, int cursorOptions,
 	result->rewindPlanIDs = glob->rewindPlanIDs;
 	result->rowMarks = glob->finalrowmarks;
 	result->relationOids = glob->relationOids;
+	/* For AcquireExecutorLocks(). */
+	if (IsModifySupportedInParallelMode(parse->commandType))
+		result->partitionOids = glob->partitionOids;
 	result->invalItems = glob->invalItems;
 	result->paramExecTypes = glob->paramExecTypes;
 	/* utilityStmt should be null, but we might as well copy it */
diff --git a/src/backend/utils/cache/plancache.c b/src/backend/utils/cache/plancache.c
index 1a0950489d..75d1088901 100644
--- a/src/backend/utils/cache/plancache.c
+++ b/src/backend/utils/cache/plancache.c
@@ -1735,6 +1735,23 @@ QueryListGetPrimaryStmt(List *stmts)
 	return NULL;
 }
 
+static void
+AcquireExecutorLocksOnPartitions(List *partitionOids, int lockmode,
+								 bool acquire)
+{
+	ListCell *lc;
+
+	foreach(lc, partitionOids)
+	{
+		Oid		partOid = lfirst_oid(lc);
+
+		if (acquire)
+			LockRelationOid(partOid, lockmode);
+		else
+			UnlockRelationOid(partOid, lockmode);
+	}
+}
+
 /*
  * AcquireExecutorLocks: acquire locks needed for execution of a cached plan;
  * or release them if acquire is false.
@@ -1748,6 +1765,8 @@ AcquireExecutorLocks(List *stmt_list, bool acquire)
 	{
 		PlannedStmt *plannedstmt = lfirst_node(PlannedStmt, lc1);
 		ListCell   *lc2;
+		Index		rti,
+					resultRelation = 0;
 
 		if (plannedstmt->commandType == CMD_UTILITY)
 		{
@@ -1765,6 +1784,9 @@ AcquireExecutorLocks(List *stmt_list, bool acquire)
 			continue;
 		}
 
+		rti = 1;
+		if (plannedstmt->resultRelations)
+			resultRelation = linitial_int(plannedstmt->resultRelations);
 		foreach(lc2, plannedstmt->rtable)
 		{
 			RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc2);
@@ -1782,6 +1804,15 @@ AcquireExecutorLocks(List *stmt_list, bool acquire)
 				LockRelationOid(rte->relid, rte->rellockmode);
 			else
 				UnlockRelationOid(rte->relid, rte->rellockmode);
+
+			/* Lock partitions ahead of modifying them in parallel mode. */
+			if (rti == resultRelation &&
+				plannedstmt->partitionOids != NIL &&
+				plannedstmt->parallelModeNeeded)
+				AcquireExecutorLocksOnPartitions(plannedstmt->partitionOids,
+												 rte->rellockmode, acquire);
+
+			rti++;
 		}
 	}
 }
diff --git a/src/include/nodes/plannodes.h b/src/include/nodes/plannodes.h
index 43160439f0..8b3923c77f 100644
--- a/src/include/nodes/plannodes.h
+++ b/src/include/nodes/plannodes.h
@@ -79,6 +79,8 @@ typedef struct PlannedStmt
 
 	List	   *relationOids;	/* OIDs of relations the plan depends on */
 
+	List	   *partitionOids;	/* OIDs of partitions the plan depends on */
+
 	List	   *invalItems;		/* other dependencies, as PlanInvalItems */
 
 	List	   *paramExecTypes; /* type OIDs for PARAM_EXEC Params */