diff --git a/src/vs/workbench/contrib/debug/browser/debugConfigurationManager.ts b/src/vs/workbench/contrib/debug/browser/debugConfigurationManager.ts
index 5751daf0cb2..275bbcc3300 100644
--- a/src/vs/workbench/contrib/debug/browser/debugConfigurationManager.ts
+++ b/src/vs/workbench/contrib/debug/browser/debugConfigurationManager.ts
@@ -105,25 +105,25 @@ export class ConfigurationManager implements IConfigurationManager {
 	}
 
 	createDebugAdapter(session: IDebugSession): IDebugAdapter | undefined {
-		let dap = this.debugAdapterFactories.get(session.configuration.type);
-		if (dap) {
-			return dap.createDebugAdapter(session);
+		let factory = this.debugAdapterFactories.get(session.configuration.type);
+		if (factory) {
+			return factory.createDebugAdapter(session);
 		}
 		return undefined;
 	}
 
 	substituteVariables(debugType: string, folder: IWorkspaceFolder | undefined, config: IConfig): Promise<IConfig> {
-		let dap = this.debugAdapterFactories.get(debugType);
-		if (dap) {
-			return dap.substituteVariables(folder, config);
+		let factory = this.debugAdapterFactories.get(debugType);
+		if (factory) {
+			return factory.substituteVariables(folder, config);
 		}
 		return Promise.resolve(config);
 	}
 
 	runInTerminal(debugType: string, args: DebugProtocol.RunInTerminalRequestArguments): Promise<number | undefined> {
-		let tl = this.debugAdapterFactories.get(debugType);
-		if (tl) {
-			return tl.runInTerminal(args);
+		let factory = this.debugAdapterFactories.get(debugType);
+		if (factory) {
+			return factory.runInTerminal(args);
 		}
 		return Promise.resolve(void 0);
 	}
diff --git a/src/vs/workbench/contrib/debug/common/debugger.ts b/src/vs/workbench/contrib/debug/common/debugger.ts
index ca1ee7ebfc3..f467b6e4cbd 100644
--- a/src/vs/workbench/contrib/debug/common/debugger.ts
+++ b/src/vs/workbench/contrib/debug/common/debugger.ts
@@ -58,19 +58,21 @@ export class Debugger implements IDebugger {
 
 			if (isObject(source)) {
 				Object.keys(source).forEach(key => {
-					if (isObject(destination[key]) && isObject(source[key])) {
-						mixin(destination[key], source[key], overwrite, level + 1);
-					} else {
-						if (key in destination) {
-							if (overwrite) {
-								if (level === 0 && key === 'type') {
-									// don't merge the 'type' property
-								} else {
-									destination[key] = source[key];
-								}
-							}
+					if (key !== '__proto__') {
+						if (isObject(destination[key]) && isObject(source[key])) {
+							mixin(destination[key], source[key], overwrite, level + 1);
 						} else {
-							destination[key] = source[key];
+							if (key in destination) {
+								if (overwrite) {
+									if (level === 0 && key === 'type') {
+										// don't merge the 'type' property
+									} else {
+										destination[key] = source[key];
+									}
+								}
+							} else {
+								destination[key] = source[key];
+							}
 						}
 					}
 				});