diff --git a/modules/ingest-common/src/main/java/org/elasticsearch/ingest/common/DateProcessor.java b/modules/ingest-common/src/main/java/org/elasticsearch/ingest/common/DateProcessor.java
index bfdf87f417b60..22db5a330fb45 100644
--- a/modules/ingest-common/src/main/java/org/elasticsearch/ingest/common/DateProcessor.java
+++ b/modules/ingest-common/src/main/java/org/elasticsearch/ingest/common/DateProcessor.java
@@ -98,7 +98,7 @@ private static ZoneId newDateTimeZone(String timezone) {
     }
 
     private static Locale newLocale(String locale) {
-        return locale == null ? Locale.ROOT : LocaleUtils.parse(locale);
+        return locale == null ? Locale.ENGLISH : LocaleUtils.parse(locale);
     }
 
     @Override