diff --git a/src/vs/vscode.proposed.d.ts b/src/vs/vscode.proposed.d.ts
index f04bacd67c2..7de595ef520 100644
--- a/src/vs/vscode.proposed.d.ts
+++ b/src/vs/vscode.proposed.d.ts
@@ -760,7 +760,14 @@ declare module 'vscode' {
 	}
 
 	export interface DebugSession {
-		getDebugProtocolBreakpoint(breakpoint: Breakpoint): DebugProtocolBreakpoint | undefined;
+		/**
+		 * Maps a VS Code breakpoint to the corresponding Debug Adapter Protocol (DAP) breakpoint that is managed by the debug adapter of the debug session.
+		 * If no DAP breakpoint exists (either because the VS Code breakpoint was not yet registered or because the debug adapter is not interested in the breakpoint), the value `undefined` is returned.
+		 *
+		 * @param breakpoint A VS Code [breakpoint](#Breakpoint).
+		 * @return A promise that resolves to the Debug Adapter Protocol breakpoint or `undefined`.
+		 */
+		getDebugProtocolBreakpoint(breakpoint: Breakpoint): Thenable<DebugProtocolBreakpoint | undefined>;
 	}
 
 	// deprecated debug API
diff --git a/src/vs/workbench/api/common/extHostDebugService.ts b/src/vs/workbench/api/common/extHostDebugService.ts
index 1e6b3429aa4..fcf987ff946 100644
--- a/src/vs/workbench/api/common/extHostDebugService.ts
+++ b/src/vs/workbench/api/common/extHostDebugService.ts
@@ -958,7 +958,7 @@ export class ExtHostDebugSession implements vscode.DebugSession {
 		return this._debugServiceProxy.$customDebugAdapterRequest(this._id, command, args);
 	}
 
-	public getDebugProtocolBreakpoint(breakpoint: vscode.Breakpoint): vscode.DebugProtocolBreakpoint | undefined {
+	public getDebugProtocolBreakpoint(breakpoint: vscode.Breakpoint): Promise<vscode.DebugProtocolBreakpoint | undefined> {
 		return this._debugServiceProxy.$getDebugProtocolBreakpoint(this._id, breakpoint.id);
 	}
 }