diff --git a/src/vs/editor/contrib/parameterHints/browser/parameterHintsWidget.ts b/src/vs/editor/contrib/parameterHints/browser/parameterHintsWidget.ts
index 24087f20469a28a665b34eb53e1b83da74e34a1d..48ece853a553d7e96cba2ff1b5c4833231b4bf96 100644
--- a/src/vs/editor/contrib/parameterHints/browser/parameterHintsWidget.ts
+++ b/src/vs/editor/contrib/parameterHints/browser/parameterHintsWidget.ts
@@ -358,7 +358,7 @@ export class ParameterHintsWidget implements IContentWidget, IDisposable {
 
 		for (let i = signature.parameters.length - 1; i >= 0; i--) {
 			const parameter = signature.parameters[i];
-			idx = signature.label.lastIndexOf(parameter.label, end);
+			idx = signature.label.lastIndexOf(parameter.label, end - 1);
 
 			let signatureLabelOffset = 0;
 			let signatureLabelEnd = 0;