diff --git a/build/lib/tsb/builder.js b/build/lib/tsb/builder.js
index cb700a54077..0bad406be79 100644
--- a/build/lib/tsb/builder.js
+++ b/build/lib/tsb/builder.js
@@ -30,7 +30,7 @@ function createTypeScriptBuilder(config, projectFile, cmd) {
     }
     let host = new LanguageServiceHost(cmd, projectFile, _log), service = ts.createLanguageService(host, ts.createDocumentRegistry()), lastBuildVersion = Object.create(null), lastDtsHash = Object.create(null), userWantsDeclarations = cmd.options.declaration, oldErrors = Object.create(null), headUsed = process.memoryUsage().heapUsed, emitSourceMapsInStream = true;
     // always emit declaraction files
-    host.getCompilationSettings().declaration = true;
+    host.getCompilationSettings().declaration = !config.transpileOnly;
     function file(file) {
         // support gulp-sourcemaps
         if (file.sourceMap) {
@@ -149,8 +149,10 @@ function createTypeScriptBuilder(config, projectFile, cmd) {
         for (let fileName of host.getScriptFileNames()) {
             if (lastBuildVersion[fileName] !== host.getScriptVersion(fileName)) {
                 toBeEmitted.push(fileName);
-                toBeCheckedSyntactically.push(fileName);
-                toBeCheckedSemantically.push(fileName);
+                if (!config.transpileOnly) {
+                    toBeCheckedSyntactically.push(fileName);
+                    toBeCheckedSemantically.push(fileName);
+                }
             }
         }
         return new Promise(resolve => {
@@ -177,7 +179,7 @@ function createTypeScriptBuilder(config, projectFile, cmd) {
                         // remember when this was build
                         newLastBuildVersion.set(fileName, host.getScriptVersion(fileName));
                         // remeber the signature
-                        if (value.signature && lastDtsHash[fileName] !== value.signature) {
+                        if (!config.transpileOnly && value.signature && lastDtsHash[fileName] !== value.signature) {
                             lastDtsHash[fileName] = value.signature;
                             filesWithChangedSignature.push(fileName);
                         }
diff --git a/build/lib/tsb/builder.ts b/build/lib/tsb/builder.ts
index d5bec6ee97b..7850d9f146d 100644
--- a/build/lib/tsb/builder.ts
+++ b/build/lib/tsb/builder.ts
@@ -14,6 +14,7 @@ import * as Vinyl from 'vinyl';
 
 export interface IConfiguration {
 	verbose: boolean;
+	transpileOnly?: boolean;
 	_emitWithoutBasePath?: boolean;
 }
 
@@ -55,8 +56,7 @@ export function createTypeScriptBuilder(config: IConfiguration, projectFile: str
 		emitSourceMapsInStream = true;
 
 	// always emit declaraction files
-	host.getCompilationSettings().declaration = true;
-
+	host.getCompilationSettings().declaration = !config.transpileOnly;
 
 	function file(file: Vinyl): void {
 		// support gulp-sourcemaps
@@ -196,8 +196,11 @@ export function createTypeScriptBuilder(config: IConfiguration, projectFile: str
 			if (lastBuildVersion[fileName] !== host.getScriptVersion(fileName)) {
 
 				toBeEmitted.push(fileName);
-				toBeCheckedSyntactically.push(fileName);
-				toBeCheckedSemantically.push(fileName);
+
+				if (!config.transpileOnly) {
+					toBeCheckedSyntactically.push(fileName);
+					toBeCheckedSemantically.push(fileName);
+				}
 			}
 		}
 
@@ -233,7 +236,7 @@ export function createTypeScriptBuilder(config: IConfiguration, projectFile: str
 						newLastBuildVersion.set(fileName, host.getScriptVersion(fileName));
 
 						// remeber the signature
-						if (value.signature && lastDtsHash[fileName] !== value.signature) {
+						if (!config.transpileOnly && value.signature && lastDtsHash[fileName] !== value.signature) {
 							lastDtsHash[fileName] = value.signature;
 							filesWithChangedSignature.push(fileName);
 						}