diff --git a/custom-words.txt b/custom-words.txt
index 1312a8690409..a162607f2476 100644
--- a/custom-words.txt
+++ b/custom-words.txt
@@ -282,6 +282,7 @@ Certificatethumbprint
 certverify
 Chademo
 chainer
+changedSince
 changepoint
 changestate
 CHECKACCESS
diff --git a/specification/cognitiveservices/data-plane/QnAMaker/stable/v4.0/QnAMaker.json b/specification/cognitiveservices/data-plane/QnAMaker/stable/v4.0/QnAMaker.json
index 2afdea67435e..78e71e4204c4 100644
--- a/specification/cognitiveservices/data-plane/QnAMaker/stable/v4.0/QnAMaker.json
+++ b/specification/cognitiveservices/data-plane/QnAMaker/stable/v4.0/QnAMaker.json
@@ -564,6 +564,12 @@
           },
           {
             "$ref": "#/parameters/Environment"
+          },
+          {
+            "$ref": "#/parameters/source"
+          },
+          {
+            "$ref": "#/parameters/changedSince"
           }
         ],
         "consumes": [
@@ -1415,6 +1421,24 @@
       "description": "Knowledgebase id.",
       "x-ms-parameter-location": "method"
     },
+    "source": {
+      "type": "string",
+      "name": "source",
+      "in": "query",
+      "required": false,
+      "x-nullable": false,
+      "description": "The source property filter to apply. Sample value: Editorial, smartLight%20FAQ.tsv .",
+      "x-ms-parameter-location": "method"
+    },
+    "changedSince": {
+      "type": "string",
+      "name": "changedSince",
+      "in": "query",
+      "required": false,
+      "x-nullable": false,
+      "description": "changedSince property is used to return all QnAs created or updated after a specific time duration. The user can filter QnAs by seconds (s), minutes (m), hours (h) and days (d). The user may use any integral value along with the suffix for time. For instance, the value of 5m returns all QnA pairs updated or created in the last 5 minutes.",
+      "x-ms-parameter-location": "method"
+    },
     "OperationId": {
       "type": "string",
       "name": "operationId",