diff --git a/src/backend/tsearch/spell.c b/src/backend/tsearch/spell.c
index 05d08cfc01..42fda514c3 100644
--- a/src/backend/tsearch/spell.c
+++ b/src/backend/tsearch/spell.c
@@ -1439,6 +1439,7 @@ NIImportAffixes(IspellDict *Conf, const char *filename)
 	Conf->usecompound = false;
 	Conf->useFlagAliases = false;
 	Conf->flagMode = FM_CHAR;
+	flag[0] = '\0';
 
 	while ((recoded = tsearch_readline(&trst)) != NULL)
 	{