diff --git a/src/vs/workbench/parts/debug/common/debug.ts b/src/vs/workbench/parts/debug/common/debug.ts
index 4693008ac5a7d9b606d58d47c4462dd79ea2e7c5..a40b47763b1c460fc3eb2a3c91da7527ad595b98 100644
--- a/src/vs/workbench/parts/debug/common/debug.ts
+++ b/src/vs/workbench/parts/debug/common/debug.ts
@@ -197,7 +197,6 @@ export interface IRawAdapter extends IRawEnvAdapter {
 export interface IRawDebugSession extends ee.EventEmitter {
 	getType(): string;
 	disconnect(restart?: boolean): TPromise<DebugProtocol.DisconnectResponse>;
-	attach(args: DebugProtocol.AttachRequestArguments): TPromise<DebugProtocol.AttachResponse>;
 
 	next(args: DebugProtocol.NextArguments): TPromise<DebugProtocol.NextResponse>;
 	stepIn(args: DebugProtocol.StepInArguments): TPromise<DebugProtocol.StepInResponse>;