diff --git a/src/backend/executor/nodeAgg.c b/src/backend/executor/nodeAgg.c
index 468db94fe5b..1059d265136 100644
--- a/src/backend/executor/nodeAgg.c
+++ b/src/backend/executor/nodeAgg.c
@@ -4318,7 +4318,7 @@ ExecEndAgg(AggState *node)
 	{
 		AggregateInstrumentation *si;
 
-		Assert(ParallelWorkerNumber <= node->shared_info->num_workers);
+		Assert(ParallelWorkerNumber < node->shared_info->num_workers);
 		si = &node->shared_info->sinstrument[ParallelWorkerNumber];
 		si->hash_batches_used = node->hash_batches_used;
 		si->hash_disk_used = node->hash_disk_used;
diff --git a/src/backend/executor/nodeIncrementalSort.c b/src/backend/executor/nodeIncrementalSort.c
index 7683e3341cd..ddefb1ac950 100644
--- a/src/backend/executor/nodeIncrementalSort.c
+++ b/src/backend/executor/nodeIncrementalSort.c
@@ -103,7 +103,7 @@
 			if ((node)->shared_info && (node)->am_worker) \
 			{ \
 				Assert(IsParallelWorker()); \
-				Assert(ParallelWorkerNumber <= (node)->shared_info->num_workers); \
+				Assert(ParallelWorkerNumber < (node)->shared_info->num_workers); \
 				instrumentSortedGroup(&(node)->shared_info->sinfo[ParallelWorkerNumber].groupName##GroupInfo, \
 									  (node)->groupName##_state); \
 			} \
diff --git a/src/backend/executor/nodeMemoize.c b/src/backend/executor/nodeMemoize.c
index 3c54ca54214..732441a398d 100644
--- a/src/backend/executor/nodeMemoize.c
+++ b/src/backend/executor/nodeMemoize.c
@@ -1109,7 +1109,7 @@ ExecEndMemoize(MemoizeState *node)
 		if (node->stats.mem_peak == 0)
 			node->stats.mem_peak = node->mem_used;
 
-		Assert(ParallelWorkerNumber <= node->shared_info->num_workers);
+		Assert(ParallelWorkerNumber < node->shared_info->num_workers);
 		si = &node->shared_info->sinstrument[ParallelWorkerNumber];
 		memcpy(si, &node->stats, sizeof(MemoizeInstrumentation));
 	}
diff --git a/src/backend/executor/nodeSort.c b/src/backend/executor/nodeSort.c
index c6c72c6e678..e9e58d07338 100644
--- a/src/backend/executor/nodeSort.c
+++ b/src/backend/executor/nodeSort.c
@@ -175,7 +175,7 @@ ExecSort(PlanState *pstate)
 			TuplesortInstrumentation *si;
 
 			Assert(IsParallelWorker());
-			Assert(ParallelWorkerNumber <= node->shared_info->num_workers);
+			Assert(ParallelWorkerNumber < node->shared_info->num_workers);
 			si = &node->shared_info->sinstrument[ParallelWorkerNumber];
 			tuplesort_get_stats(tuplesortstate, si);
 		}