diff --git a/src/compiler/watch.ts b/src/compiler/watch.ts
index 530eb4d31e0..f53f01e3eb2 100644
--- a/src/compiler/watch.ts
+++ b/src/compiler/watch.ts
@@ -127,7 +127,7 @@ namespace ts {
     /**
      * Helper that emit files, report diagnostics and lists emitted and/or source files depending on compiler options
      */
-    export function emitFilesAndReportErrors(program: ProgramToEmitFilesAndReportErrors, reportDiagnostic: DiagnosticReporter, reportSummary?: ReportEmitErrorSummary, writeFileName?: (s: string) => void) {
+    export function emitFilesAndReportErrors(program: ProgramToEmitFilesAndReportErrors, reportDiagnostic: DiagnosticReporter, writeFileName?: (s: string) => void, reportSummary?: ReportEmitErrorSummary) {
         // First get and report any syntactic errors.
         const diagnostics = program.getConfigFileParsingDiagnostics().slice();
         const configFileParsingDiagnosticsLength = diagnostics.length;
@@ -242,7 +242,7 @@ namespace ts {
                 }
             };
 
-            emitFilesAndReportErrors(builderProgram, reportDiagnostic, reportSummary, writeFileName);
+            emitFilesAndReportErrors(builderProgram, reportDiagnostic, writeFileName, reportSummary);
         }
     }
 
diff --git a/src/harness/unittests/tscWatchMode.ts b/src/harness/unittests/tscWatchMode.ts
index 9965489ca71..99bad3e3091 100644
--- a/src/harness/unittests/tscWatchMode.ts
+++ b/src/harness/unittests/tscWatchMode.ts
@@ -128,6 +128,12 @@ namespace ts.tscWatch {
         }
     }
 
+    function createErrorsFoundCompilerDiagnostic(errors: ReadonlyArray<Diagnostic>) {
+        return errors.length === 1
+            ? createCompilerDiagnostic(Diagnostics.Found_1_error)
+            : createCompilerDiagnostic(Diagnostics.Found_0_errors, errors.length);
+    }
+
     function checkOutputErrorsInitial(host: WatchedSystem, errors: ReadonlyArray<Diagnostic>, disableConsoleClears?: boolean, logsBeforeErrors?: string[]) {
         checkOutputErrors(
             host,
@@ -136,9 +142,7 @@ namespace ts.tscWatch {
             logsBeforeErrors,
             errors,
             disableConsoleClears,
-            errors.length === 1
-                ? createCompilerDiagnostic(Diagnostics.Found_1_error)
-                : createCompilerDiagnostic(Diagnostics.Found_0_errors, errors.length),
+            createErrorsFoundCompilerDiagnostic(errors),
             createCompilerDiagnostic(Diagnostics.Compilation_complete_Watching_for_file_changes));
     }
 
@@ -150,9 +154,7 @@ namespace ts.tscWatch {
             logsBeforeErrors,
             errors,
             disableConsoleClears,
-            errors.length === 1
-                ? createCompilerDiagnostic(Diagnostics.Found_1_error)
-                : createCompilerDiagnostic(Diagnostics.Found_0_errors, errors.length),
+            createErrorsFoundCompilerDiagnostic(errors),
             createCompilerDiagnostic(Diagnostics.Compilation_complete_Watching_for_file_changes));
     }