diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index ea7ec2729a9..1c8c7b95dad 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -3823,11 +3823,11 @@ PostgresMain(int argc, char *argv[],
 			 const char *dbname,
 			 const char *username)
 {
-	int			firstchar;
-	StringInfoData input_message;
 	sigjmp_buf	local_sigjmp_buf;
+
+	/* these must be volatile to ensure state is preserved across longjmp: */
 	volatile bool send_ready_for_query = true;
-	bool		disable_idle_in_transaction_timeout = false;
+	volatile bool disable_idle_in_transaction_timeout = false;
 
 	/* Initialize startup process environment if necessary. */
 	if (!IsUnderPostmaster)
@@ -4111,8 +4111,9 @@ PostgresMain(int argc, char *argv[],
 		 * query cancels from being misreported as timeouts in case we're
 		 * forgetting a timeout cancel.
 		 */
-		disable_all_timeouts(false);
-		QueryCancelPending = false; /* second to avoid race condition */
+		disable_all_timeouts(false);	/* do first to avoid race condition */
+		QueryCancelPending = false;
+		disable_idle_in_transaction_timeout = false;
 
 		/* Not reading from the client anymore. */
 		DoingCommandRead = false;
@@ -4201,6 +4202,9 @@ PostgresMain(int argc, char *argv[],
 
 	for (;;)
 	{
+		int			firstchar;
+		StringInfoData input_message;
+
 		/*
 		 * At top of loop, reset extended-query-message flag, so that any
 		 * errors encountered in "idle" state don't provoke skip.