diff --git a/testproxy/known_failures.txt b/testproxy/known_failures.txt
index 425ea9cd0..229bbe011 100644
--- a/testproxy/known_failures.txt
+++ b/testproxy/known_failures.txt
@@ -17,7 +17,6 @@ TestReadRows_Retry_WithRetryInfo_MultipleErrorResponse\|
 TestCheckAndMutateRow_Generic_DeadlineExceeded\|
 TestCheckAndMutateRow_NoRetry_TrueMutations\|
 TestCheckAndMutateRow_NoRetry_FalseMutations\|
-TestCheckAndMutateRow_Generic_CloseClient\|
 TestCheckAndMutateRow_Generic_MultiStreams\|
 TestSampleRowKeys_Generic_DeadlineExceeded\|
 TestSampleRowKeys_Retry_WithRoutingCookie\|
diff --git a/testproxy/services/check-and-mutate-row.js b/testproxy/services/check-and-mutate-row.js
index efbcf6d4f..3a7a38419 100644
--- a/testproxy/services/check-and-mutate-row.js
+++ b/testproxy/services/check-and-mutate-row.js
@@ -79,15 +79,15 @@ const checkAndMutateRow = ({clientMap}) =>
     const filter = [];
     const filterConfig = {onMatch, onNoMatch};
     try {
-      const result = await row.filter(filter, filterConfig);
+      const [, result] = await row.filter(filter, filterConfig);
       return {
         status: {code: grpc.status.OK, details: []},
-        row: result,
+        result,
       };
     } catch (e) {
       return {
         status: {
-          code: e.code,
+          code: e.code ? e.code : grpc.status.UNKNOWN,
           details: [],
           message: e.message,
         },