diff --git a/src/server/protocol.d.ts b/src/server/protocol.d.ts
index 73ef396a7e4..62162b3237c 100644
--- a/src/server/protocol.d.ts
+++ b/src/server/protocol.d.ts
@@ -904,7 +904,6 @@ declare namespace ts.server.protocol {
      * Arguments of a signature help request.
      */
     export interface SignatureHelpRequestArgs extends FileLocationRequestArgs {
-
     }
 
     /**
@@ -923,6 +922,32 @@ declare namespace ts.server.protocol {
         body?: SignatureHelpItems;
     }
 
+    /**
+      * Synchronous request for semantic diagnostics of one file.
+      */
+    export interface SemanticDiagnosticsSyncRequest extends FileRequest {
+    }
+
+    /**
+      * Response object for synchronous sematic diagnostics request.
+      */
+    export interface SemanticDiagnosticsSyncResponse extends Response {
+        body?: Diagnostic[];
+    }
+
+    /**
+      * Synchronous request for syntactic diagnostics of one file.
+      */
+    export interface SyntacticDiagnosticsSyncRequest extends FileRequest {
+    }
+
+    /**
+      * Response object for synchronous syntactic diagnostics request.
+      */
+    export interface SyntacticDiagnosticsSyncResponse extends Response {
+        body?: Diagnostic[];
+    }
+
     /**
     * Arguments for GeterrForProject request.
     */