diff --git a/extensions/configuration-editing/src/configurationEditingMain.ts b/extensions/configuration-editing/src/configurationEditingMain.ts
index 822668f6fb5..9e7f2d247de 100644
--- a/extensions/configuration-editing/src/configurationEditingMain.ts
+++ b/extensions/configuration-editing/src/configurationEditingMain.ts
@@ -57,6 +57,7 @@ function registerVariableCompletions(pattern: string): vscode.Disposable {
 					{ label: 'fileBasename', detail: localize('fileBasename', "The current opened file's basename") },
 					{ label: 'fileBasenameNoExtension', detail: localize('fileBasenameNoExtension', "The current opened file's basename with no file extension") },
 					{ label: 'defaultBuildTask', detail: localize('defaultBuildTask', "The name of the default build task. If there is not a single default build task then a quick pick is shown to choose the build task.") },
+					{ label: 'pathSeparator', detail: localize('pathSeparator', "The character used by the operating system to separate components in file paths") },
 				].map(variable => ({
 					label: '${' + variable.label + '}',
 					range: new vscode.Range(startPosition, position),