diff --git a/src/backend/utils/adt/pg_lsn.c b/src/backend/utils/adt/pg_lsn.c
index b4c6c23..90e9b8c 100644
--- a/src/backend/utils/adt/pg_lsn.c
+++ b/src/backend/utils/adt/pg_lsn.c
@@ -34,6 +34,9 @@ pg_lsn_in_internal(const char *str, bool *have_error)
 				off;
 	XLogRecPtr	result;
 
+	Assert(have_error != NULL);
+	*have_error = false;
+
 	/* Sanity check input format. */
 	len1 = strspn(str, "0123456789abcdefABCDEF");
 	if (len1 < 1 || len1 > MAXPG_LSNCOMPONENT || str[len1] != '/')
@@ -61,7 +64,7 @@ pg_lsn_in(PG_FUNCTION_ARGS)
 {
 	char	   *str = PG_GETARG_CSTRING(0);
 	XLogRecPtr	result;
-	bool		have_error = false;
+	bool		have_error;
 
 	result = pg_lsn_in_internal(str, &have_error);
 	if (have_error)
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index fc46360..ce179fc 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -11677,7 +11677,7 @@ check_recovery_target_lsn(char **newval, void **extra, GucSource source)
 	{
 		XLogRecPtr	lsn;
 		XLogRecPtr *myextra;
-		bool		have_error = false;
+		bool		have_error;
 
 		lsn = pg_lsn_in_internal(*newval, &have_error);
 		if (have_error)