diff --git a/src/vs/workbench/parts/debug/node/debugAdapter.ts b/src/vs/workbench/parts/debug/node/debugAdapter.ts
index e1d6edd70ba..f85d5996594 100644
--- a/src/vs/workbench/parts/debug/node/debugAdapter.ts
+++ b/src/vs/workbench/parts/debug/node/debugAdapter.ts
@@ -227,7 +227,7 @@ export class Adapter {
 			};
 			Object.keys(attributes.properties).forEach(name => {
 				// Use schema allOf property to get independent error reporting #21113
-				attributes.properties[name].pattern = attributes.properties[name].pattern || '^(?!\\$\\{(env|config|command)\\.)';
+				attributes.properties[name].pattern = attributes.properties[name].pattern || '^(?!\\s*\\$\\{(env|config|command)\\.)';
 				attributes.properties[name].patternErrorMessage = attributes.properties[name].patternErrorMessage ||
 					nls.localize('deprecatedVariables', "'env.', 'config.' and 'command.' are deprecated, use 'env:', 'config:' and 'command:' instead.");
 			});