diff --git a/src/harness/harness.ts b/src/harness/harness.ts
index 9e6978f2a15..9fe26ed51c3 100644
--- a/src/harness/harness.ts
+++ b/src/harness/harness.ts
@@ -304,14 +304,13 @@ namespace Utils {
                 o.containsParseError = true;
             }
 
-            ts.forEach(Object.getOwnPropertyNames(n), propertyName => {
+            for (const propertyName of Object.getOwnPropertyNames(n) as ReadonlyArray<keyof ts.SourceFile | keyof ts.Identifier>) {
                 switch (propertyName) {
                     case "parent":
                     case "symbol":
                     case "locals":
                     case "localSymbol":
                     case "kind":
-                    case "semanticDiagnostics":
                     case "id":
                     case "nodeCount":
                     case "symbolCount":
@@ -334,7 +333,6 @@ namespace Utils {
                         }
                         break;
 
-                    case "referenceDiagnostics":
                     case "parseDiagnostics":
                         o[propertyName] = convertDiagnostics((<any>n)[propertyName]);
                         break;
@@ -355,9 +353,7 @@ namespace Utils {
                     default:
                         o[propertyName] = (<any>n)[propertyName];
                 }
-
-                return undefined;
-            });
+            }
 
             return o;
         }
diff --git a/src/services/services.ts b/src/services/services.ts
index 9b427452650..f17b7698a87 100644
--- a/src/services/services.ts
+++ b/src/services/services.ts
@@ -546,7 +546,6 @@ namespace ts {
         public typeReferenceDirectives: FileReference[];
 
         public syntacticDiagnostics: Diagnostic[];
-        public referenceDiagnostics: Diagnostic[];
         public parseDiagnostics: Diagnostic[];
         public bindDiagnostics: Diagnostic[];