diff --git a/src/backend/commands/collationcmds.c b/src/backend/commands/collationcmds.c
index 4075f991a0..8fe8227751 100644
--- a/src/backend/commands/collationcmds.c
+++ b/src/backend/commands/collationcmds.c
@@ -597,11 +597,15 @@ pg_import_system_collations(PG_FUNCTION_ARGS)
 			enc = pg_get_encoding_from_locale(localebuf, false);
 			if (enc < 0)
 			{
-				/* error message printed by pg_get_encoding_from_locale() */
+				elog(DEBUG1, "could not identify encoding for locale \"%s\"",
+					 localebuf);
 				continue;
 			}
 			if (!PG_VALID_BE_ENCODING(enc))
-				continue;		/* ignore locales for client-only encodings */
+			{
+				elog(DEBUG1, "skipping client-only locale \"%s\"", localebuf);
+				continue;
+			}
 			if (enc == PG_SQL_ASCII)
 				continue;		/* C/POSIX are already in the catalog */