diff --git a/tests/perfsys.ts b/tests/perfsys.ts
index d2e3215c56c..a54844da7b9 100644
--- a/tests/perfsys.ts
+++ b/tests/perfsys.ts
@@ -8,13 +8,11 @@ module perftest {
 
     export interface IO {
         getOut(): string;
-        getErr(): string;
     }
 
     export var readFile = sys.readFile;
     var writeFile = sys.writeFile;
     export var write = sys.write;
-    export var writeErr = sys.writeErr;
     var resolvePath = sys.resolvePath;
     export var getExecutingFilePath = sys.getExecutingFilePath;
     export var getCurrentDirectory = sys.getCurrentDirectory;
@@ -22,12 +20,12 @@ module perftest {
     var args = sys.args;
 
     // augment sys so first ts.executeCommandLine call will be finish silently
-    sys.writeErr = (s: string) => { };
+    sys.write = (s: string) => { };
     sys.args = []
 
     export function restoreSys() {
         sys.args = args;
-        sys.writeErr = writeErr;
+        sys.write = write;
     }
 
     export function hasLogIOFlag() {
@@ -96,11 +94,9 @@ module perftest {
         var err: string = "";
 
         sys.write = (s: string) => { out += s; };
-        sys.writeErr = (s: string) => { err += s; };
 
         return {
             getOut: () => out,
-            getErr: () => err
         };
     }
 }
diff --git a/tests/perftc.ts b/tests/perftc.ts
index 6ab29de0061..ccb5f608164 100644
--- a/tests/perftc.ts
+++ b/tests/perftc.ts
@@ -8,13 +8,14 @@ if (perftest.hasLogIOFlag()) {
     var compilerHost: ts.CompilerHost = {
         getSourceFile: (s, v) => {
             var content = perftest.readFile(s);
-            return content !== undefined ? ts.createSourceFile(s, content, v) : undefined;
+            return content !== undefined ? ts.createSourceFile(s, content, v, ts.ByteOrderMark.Utf8) : undefined;
         },
         getDefaultLibFilename: () => ts.combinePaths(ts.getDirectoryPath(ts.normalizePath(perftest.getExecutingFilePath())), "lib.d.ts"),
         writeFile: (f: string, content: string) => { throw new Error("Unexpected operation: writeFile"); },
         getCurrentDirectory: () => perftest.getCurrentDirectory(),
-        getCanonicalFileName: getCanonicalFileName,
-        useCaseSensitiveFileNames: () => sys.useCaseSensitiveFileNames
+        getCanonicalFileName: ts.getCanonicalFileName,
+        useCaseSensitiveFileNames: () => sys.useCaseSensitiveFileNames,
+        getNewLine: () => sys.newLine
     };
 
     var commandLine = ts.parseCommandLine(perftest.getArgsWithoutLogIOFlag());
@@ -26,5 +27,4 @@ else {
     var io = perftest.prepare();
     ts.executeCommandLine(perftest.getArgsWithoutIOLogFile());
     perftest.write(io.getOut());
-    perftest.writeErr(io.getErr());
 }