diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 81d2687495..9a9724574b 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -1825,6 +1825,8 @@ CommitTransaction(void)
 			break;
 	}
 
+	CallXactCallbacks(XACT_EVENT_PRE_COMMIT);
+
 	/*
 	 * The remaining actions cannot call any user-defined code, so it's safe
 	 * to start shutting down within-transaction services.	But note that most
@@ -2028,6 +2030,8 @@ PrepareTransaction(void)
 			break;
 	}
 
+	CallXactCallbacks(XACT_EVENT_PRE_PREPARE);
+
 	/*
 	 * The remaining actions cannot call any user-defined code, so it's safe
 	 * to start shutting down within-transaction services.	But note that most
@@ -4058,8 +4062,12 @@ CommitSubTransaction(void)
 		elog(WARNING, "CommitSubTransaction while in %s state",
 			 TransStateAsString(s->state));
 
-	/* Pre-commit processing goes here -- nothing to do at the moment */
+	/* Pre-commit processing goes here */
 
+	CallSubXactCallbacks(SUBXACT_EVENT_PRE_COMMIT_SUB, s->subTransactionId,
+						 s->parent->subTransactionId);
+
+	/* Do the actual "commit", such as it is */
 	s->state = TRANS_COMMIT;
 
 	/* Must CCI to ensure commands of subtransaction are seen as done */
diff --git a/src/include/access/xact.h b/src/include/access/xact.h
index fcdff93272..8cadc54971 100644
--- a/src/include/access/xact.h
+++ b/src/include/access/xact.h
@@ -76,7 +76,9 @@ typedef enum
 {
 	XACT_EVENT_COMMIT,
 	XACT_EVENT_ABORT,
-	XACT_EVENT_PREPARE
+	XACT_EVENT_PREPARE,
+	XACT_EVENT_PRE_COMMIT,
+	XACT_EVENT_PRE_PREPARE
 } XactEvent;
 
 typedef void (*XactCallback) (XactEvent event, void *arg);
@@ -85,7 +87,8 @@ typedef enum
 {
 	SUBXACT_EVENT_START_SUB,
 	SUBXACT_EVENT_COMMIT_SUB,
-	SUBXACT_EVENT_ABORT_SUB
+	SUBXACT_EVENT_ABORT_SUB,
+	SUBXACT_EVENT_PRE_COMMIT_SUB
 } SubXactEvent;
 
 typedef void (*SubXactCallback) (SubXactEvent event, SubTransactionId mySubid,
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index 591a432f54..70e67d9eb7 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -6150,7 +6150,7 @@ plpgsql_xact_cb(XactEvent event, void *arg)
 	 * expect the regular abort recovery procedures to release everything of
 	 * interest.
 	 */
-	if (event != XACT_EVENT_ABORT)
+	if (event == XACT_EVENT_COMMIT || event == XACT_EVENT_PREPARE)
 	{
 		/* Shouldn't be any econtext stack entries left at commit */
 		Assert(simple_econtext_stack == NULL);
@@ -6159,7 +6159,7 @@ plpgsql_xact_cb(XactEvent event, void *arg)
 			FreeExecutorState(simple_eval_estate);
 		simple_eval_estate = NULL;
 	}
-	else
+	else if (event == XACT_EVENT_ABORT)
 	{
 		simple_econtext_stack = NULL;
 		simple_eval_estate = NULL;
@@ -6178,19 +6178,19 @@ void
 plpgsql_subxact_cb(SubXactEvent event, SubTransactionId mySubid,
 				   SubTransactionId parentSubid, void *arg)
 {
-	if (event == SUBXACT_EVENT_START_SUB)
-		return;
-
-	while (simple_econtext_stack != NULL &&
-		   simple_econtext_stack->xact_subxid == mySubid)
+	if (event == SUBXACT_EVENT_COMMIT_SUB || event == SUBXACT_EVENT_ABORT_SUB)
 	{
-		SimpleEcontextStackEntry *next;
+		while (simple_econtext_stack != NULL &&
+			   simple_econtext_stack->xact_subxid == mySubid)
+		{
+			SimpleEcontextStackEntry *next;
 
-		FreeExprContext(simple_econtext_stack->stack_econtext,
-						(event == SUBXACT_EVENT_COMMIT_SUB));
-		next = simple_econtext_stack->next;
-		pfree(simple_econtext_stack);
-		simple_econtext_stack = next;
+			FreeExprContext(simple_econtext_stack->stack_econtext,
+							(event == SUBXACT_EVENT_COMMIT_SUB));
+			next = simple_econtext_stack->next;
+			pfree(simple_econtext_stack);
+			simple_econtext_stack = next;
+		}
 	}
 }