diff --git a/src/vs/workbench/parts/debug/common/debug.ts b/src/vs/workbench/parts/debug/common/debug.ts
index 273b656a2fd660573ed38e21f43e6bdf46fe5a28..cadd6efb32b67a4cedb269fc9dcc11f086cfce8a 100644
--- a/src/vs/workbench/parts/debug/common/debug.ts
+++ b/src/vs/workbench/parts/debug/common/debug.ts
@@ -173,7 +173,7 @@ export interface IStackFrame extends ITreeElement {
 	source: Source;
 	getScopes(): TPromise<IScope[]>;
 	restart(): TPromise<any>;
-	completions(text: string, position: Position): TPromise<ISuggestion[]>;
+	completions(text: string, position: Position, overwriteBefore: number): TPromise<ISuggestion[]>;
 }
 
 export interface IEnablement extends ITreeElement {
diff --git a/src/vs/workbench/parts/debug/common/debugModel.ts b/src/vs/workbench/parts/debug/common/debugModel.ts
index 7a925ece172122f663fe4e853d418b28a1de0eb9..5d16733beb80fb71640216554874e1c1e96436e2 100644
--- a/src/vs/workbench/parts/debug/common/debugModel.ts
+++ b/src/vs/workbench/parts/debug/common/debugModel.ts
@@ -354,7 +354,7 @@ export class StackFrame implements debug.IStackFrame {
 		return this.thread.process.session.restartFrame({ frameId: this.frameId });
 	}
 
-	public completions(text: string, position: Position): TPromise<ISuggestion[]> {
+	public completions(text: string, position: Position, overwriteBefore: number): TPromise<ISuggestion[]> {
 		if (!this.thread.process.session.configuration.capabilities.supportsCompletionsRequest) {
 			return TPromise.as([]);
 		}
@@ -365,10 +365,11 @@ export class StackFrame implements debug.IStackFrame {
 			column: position.column,
 			line: position.lineNumber
 		}).then(response => {
-			return response && response.body && response.body.targets ? response.body.targets.map(item => ({
+			return response && response.body && response.body.targets ? response.body.targets.map(item => (<ISuggestion>{
 				label: item.label,
 				insertText: item.text || item.label,
-				type: item.type
+				type: item.type,
+				overwriteBefore: item.length || overwriteBefore
 			})) : [];
 		}, err => []);
 	}
diff --git a/src/vs/workbench/parts/debug/electron-browser/repl.ts b/src/vs/workbench/parts/debug/electron-browser/repl.ts
index d964d1b7f3d50f90f1e6eb8a1e2a3a5831aa4fa4..fadd4be2035be6e61e08250e47d6dc60736ebb7e 100644
--- a/src/vs/workbench/parts/debug/electron-browser/repl.ts
+++ b/src/vs/workbench/parts/debug/electron-browser/repl.ts
@@ -172,12 +172,12 @@ export class Repl extends Panel implements IPrivateReplService {
 			triggerCharacters: ['.'],
 			provideCompletionItems: (model: IReadOnlyModel, position: Position, token: CancellationToken): Thenable<modes.ISuggestResult> => {
 				const word = this.replInput.getModel().getWordAtPosition(position);
+				const overwriteBefore = word ? word.word.length : 0;
 				const text = this.replInput.getModel().getLineContent(position.lineNumber);
 				const focusedStackFrame = this.debugService.getViewModel().focusedStackFrame;
-				const completions = focusedStackFrame ? focusedStackFrame.completions(text, position) : TPromise.as([]);
+				const completions = focusedStackFrame ? focusedStackFrame.completions(text, position, overwriteBefore) : TPromise.as([]);
 				return wireCancellationToken(token, completions.then(suggestions => ({
-					currentWord: word ? word.word : '',
-					suggestions
+					suggestions: suggestions
 				})));
 			}
 		},