diff --git a/src/compiler/tsc.ts b/src/compiler/tsc.ts
index 744379aa696..149439d9b67 100644
--- a/src/compiler/tsc.ts
+++ b/src/compiler/tsc.ts
@@ -49,7 +49,7 @@ namespace ts {
     }
 
     export function executeCommandLine(args: string[]): void {
-        if ((args[0].toLowerCase() === "--build") || (args[0].toLowerCase() === "-b")) {
+        if (args.length > 0 && ((args[0].toLowerCase() === "--build") || (args[0].toLowerCase() === "-b"))) {
             return performBuild(createCompilerHost({}), createDiagnosticReporter(sys), args.slice(1), sys);
         }