diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 01b6cc1f7d3..56d8b0814b5 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -4111,12 +4111,11 @@ PostgresSingleUserMain(int argc, char *argv[],
 void
 PostgresMain(const char *dbname, const char *username)
 {
-	int			firstchar;
 	StringInfoData input_message;
 	sigjmp_buf	local_sigjmp_buf;
 	volatile bool send_ready_for_query = true;
-	bool		idle_in_transaction_timeout_enabled = false;
-	bool		idle_session_timeout_enabled = false;
+	volatile bool idle_in_transaction_timeout_enabled = false;
+	volatile bool idle_session_timeout_enabled = false;
 
 	Assert(dbname != NULL);
 	Assert(username != NULL);
@@ -4418,6 +4417,8 @@ PostgresMain(const char *dbname, const char *username)
 
 	for (;;)
 	{
+		int			firstchar;
+
 		/*
 		 * At top of loop, reset extended-query-message flag, so that any
 		 * errors encountered in "idle" state don't provoke skip.