diff --git a/src/common.js b/src/common.js
index 6d571d28..e3291b20 100644
--- a/src/common.js
+++ b/src/common.js
@@ -179,7 +179,7 @@ function setup(env) {
 			namespaces = split[i].replace(/\*/g, '.*?');
 
 			if (namespaces[0] === '-') {
-				createDebug.skips.push(new RegExp('^' + namespaces.substr(1) + '$'));
+				createDebug.skips.push(new RegExp('^' + namespaces.slice(1) + '$'));
 			} else {
 				createDebug.names.push(new RegExp('^' + namespaces + '$'));
 			}