diff --git a/specification/_json_spec/async_search.submit.json b/specification/_json_spec/async_search.submit.json
index 5fff0dd9ae..bfb55ef4ba 100644
--- a/specification/_json_spec/async_search.submit.json
+++ b/specification/_json_spec/async_search.submit.json
@@ -69,8 +69,8 @@
       },
       "default_operator": {
         "type": "enum",
-        "options": ["AND", "OR"],
-        "default": "OR",
+        "options": ["and", "or"],
+        "default": "or",
         "description": "The default operator for query string query (AND or OR)"
       },
       "df": {
diff --git a/specification/_json_spec/count.json b/specification/_json_spec/count.json
index 06f4355473..8581ac3ef2 100644
--- a/specification/_json_spec/count.json
+++ b/specification/_json_spec/count.json
@@ -81,8 +81,8 @@
       },
       "default_operator": {
         "type": "enum",
-        "options": ["AND", "OR"],
-        "default": "OR",
+        "options": ["and", "or"],
+        "default": "or",
         "description": "The default operator for query string query (AND or OR)"
       },
       "df": {
diff --git a/specification/_json_spec/delete_by_query.json b/specification/_json_spec/delete_by_query.json
index f6608f6e7c..d77e88bcab 100644
--- a/specification/_json_spec/delete_by_query.json
+++ b/specification/_json_spec/delete_by_query.json
@@ -36,8 +36,8 @@
       },
       "default_operator": {
         "type": "enum",
-        "options": ["AND", "OR"],
-        "default": "OR",
+        "options": ["and", "or"],
+        "default": "or",
         "description": "The default operator for query string query (AND or OR)"
       },
       "df": {
diff --git a/specification/_json_spec/explain.json b/specification/_json_spec/explain.json
index 4f9af89a24..53630185d1 100644
--- a/specification/_json_spec/explain.json
+++ b/specification/_json_spec/explain.json
@@ -40,8 +40,8 @@
       },
       "default_operator": {
         "type": "enum",
-        "options": ["AND", "OR"],
-        "default": "OR",
+        "options": ["and", "or"],
+        "default": "or",
         "description": "The default operator for query string query (AND or OR)"
       },
       "df": {
diff --git a/specification/_json_spec/indices.validate_query.json b/specification/_json_spec/indices.validate_query.json
index 9c19336704..33eda568f8 100644
--- a/specification/_json_spec/indices.validate_query.json
+++ b/specification/_json_spec/indices.validate_query.json
@@ -65,8 +65,8 @@
       },
       "default_operator": {
         "type": "enum",
-        "options": ["AND", "OR"],
-        "default": "OR",
+        "options": ["and", "or"],
+        "default": "or",
         "description": "The default operator for query string query (AND or OR)"
       },
       "df": {
diff --git a/specification/_json_spec/search.json b/specification/_json_spec/search.json
index d4212c7030..89985d7dd3 100644
--- a/specification/_json_spec/search.json
+++ b/specification/_json_spec/search.json
@@ -45,8 +45,8 @@
       },
       "default_operator": {
         "type": "enum",
-        "options": ["AND", "OR"],
-        "default": "OR",
+        "options": ["and", "or"],
+        "default": "or",
         "description": "The default operator for query string query (AND or OR)"
       },
       "df": {
diff --git a/specification/_json_spec/update_by_query.json b/specification/_json_spec/update_by_query.json
index d490a39a89..325feca2b1 100644
--- a/specification/_json_spec/update_by_query.json
+++ b/specification/_json_spec/update_by_query.json
@@ -36,8 +36,8 @@
       },
       "default_operator": {
         "type": "enum",
-        "options": ["AND", "OR"],
-        "default": "OR",
+        "options": ["and", "or"],
+        "default": "or",
         "description": "The default operator for query string query (AND or OR)"
       },
       "df": {