diff --git a/lib/attribute.js b/lib/attribute.js
index 67f526a..cd88214 100644
--- a/lib/attribute.js
+++ b/lib/attribute.js
@@ -31,7 +31,7 @@ attribute.ignoreProperties = {
 var validators = attribute.validators = {};
 
 /**
- * Validates whether the instance if of a certain type
+ * Validates whether the instance is of a certain type
  * @param instance
  * @param schema
  * @param options
@@ -947,7 +947,7 @@ validators['const'] = function validateEnum (instance, schema, options, ctx) {
 };
 
 /**
- * Validates whether the instance if of a prohibited type.
+ * Validates whether the instance is of a prohibited type.
  * @param instance
  * @param schema
  * @param options