diff --git a/JBBCode/CodeDefinitionBuilder.php b/JBBCode/CodeDefinitionBuilder.php
index cf5c1bb..bec8983 100644
--- a/JBBCode/CodeDefinitionBuilder.php
+++ b/JBBCode/CodeDefinitionBuilder.php
@@ -3,12 +3,14 @@
 namespace JBBCode;
 
 require_once "CodeDefinition.php";
+require_once "validators/CallableValidatorAdapter.php";
 
 /**
  * Implements the builder pattern for the CodeDefinition class. A builder
  * is the recommended way of constructing CodeDefinition objects.
  *
  * @author jbowens
+ * @author Kubo2
  */
 class CodeDefinitionBuilder
 {
@@ -111,14 +113,15 @@ public function setNestLimit($limit)
     /**
      * Sets the InputValidator that option arguments should be validated with.
      *
-     * @param InputValidator $validator  the InputValidator instance to use
+     * @param InputValidator|callable $validator  the validator to use when validating input
      * @return self
      */
-    public function setOptionValidator(InputValidator $validator, $option=null)
+    public function setOptionValidator($validator, $option=null)
     {
         if(empty($option)){
             $option = $this->tagName;
         }
+        $validator = $this->checkInputValidator($validator);
         $this->optionValidator[$option] = $validator;
         return $this;
     }
@@ -126,11 +129,12 @@ public function setOptionValidator(InputValidator $validator, $option=null)
     /**
      * Sets the InputValidator that body ({param}) text should be validated with.
      *
-     * @param InputValidator $validator  the InputValidator instance to use
+     * @param InputValidator|callable $validator  the validator to use when validating input
      * @return self
      */
-    public function setBodyValidator(InputValidator $validator)
+    public function setBodyValidator($validator)
     {
+        $validator = $this->checkInputValidator($validator);
         $this->bodyValidator = $validator;
         return $this;
     }
@@ -158,6 +162,26 @@ public function removeBodyValidator()
         return $this;
     }
 
+    /**
+     * Checks if `$validator` is a valid input validator, otherwise throws an exception
+     *
+     * @internal
+     * @return InputValidator
+     * @throws \InvalidArgumentException
+     */
+    private function checkInputValidator($validator) {
+        if($validator instanceof InputValidator) {
+            return $validator;
+        } elseif(is_callable($validator)) {
+            return new validators\CallableValidatorAdapter($validator);
+        } else {
+            throw new \InvalidArgumentException(
+                '$validator must be either of type callable, or an instance of JBBCode\InputValidator, ' .
+                (is_object($validator) ? get_class($validator) : gettype($validator)) . ' given'
+            );
+        }
+    }
+
     /**
      * Builds a CodeDefinition with the current state of the builder.
      *
diff --git a/JBBCode/InputValidator.php b/JBBCode/InputValidator.php
index 6320b87..196d4bb 100644
--- a/JBBCode/InputValidator.php
+++ b/JBBCode/InputValidator.php
@@ -13,7 +13,7 @@ interface InputValidator
 {
 
     /**
-     * Returns true iff the given input is valid, false otherwise.
+     * Returns true if the given input is valid, false otherwise.
      * @param string $input
      * @return boolean
      */
diff --git a/JBBCode/tests/ValidatorTest.php b/JBBCode/tests/ValidatorTest.php
index e7dacb0..52b9cbd 100644
--- a/JBBCode/tests/ValidatorTest.php
+++ b/JBBCode/tests/ValidatorTest.php
@@ -1,13 +1,15 @@
 <?php
 
-require_once dirname(dirname(__FILE__)) . DIRECTORY_SEPARATOR . 'Parser.php';
-require_once dirname(dirname(__FILE__)) . DIRECTORY_SEPARATOR . 'validators' . DIRECTORY_SEPARATOR . 'UrlValidator.php';
-require_once dirname(dirname(__FILE__)) . DIRECTORY_SEPARATOR . 'validators' . DIRECTORY_SEPARATOR . 'CssColorValidator.php';
+require_once __DIR__ . '/../Parser.php';
+require_once __DIR__ . '/../validators/UrlValidator.php';
+require_once __DIR__ . '/../validators/CssColorValidator.php';
+require_once __DIR__ . '/../validators/CallableValidatorAdapter.php';
 
 /**
  * Test cases for InputValidators.
  *
  * @author jbowens
+ * @author Kubo2
  * @since May 2013
  */
 class ValidatorTest extends PHPUnit_Framework_TestCase
@@ -148,4 +150,15 @@ public function testInvalidColorBBCode()
                 $parser->getAsHtml());
     }
 
+    /**
+     * Test functionality of {@link JBBCode\CallableValidatorAdapter}
+     */
+    public function testCallableValidatorAdapter() {
+        $emptyValidator = new \JBBCode\validators\CallableValidatorAdapter(function($input) {
+            return empty($input);
+        });
+        $this->assertTrue($emptyValidator->validate(''));
+        $this->assertFalse($emptyValidator->validate('Hey! I am here'));
+    }
+
 }
diff --git a/JBBCode/validators/CallableValidatorAdapter.php b/JBBCode/validators/CallableValidatorAdapter.php
new file mode 100644
index 0000000..bff5fcd
--- /dev/null
+++ b/JBBCode/validators/CallableValidatorAdapter.php
@@ -0,0 +1,40 @@
+<?php
+
+namespace JBBCode\validators;
+
+use JBBCode,
+	JBBCode\InputValidator;
+
+require_once __DIR__ . '/../InputValidator.php';
+
+/**
+ * An adapter for callable input validator.
+ * 
+ * This class is most often created by {@link CodeDefinitionBuilder}
+ * and used as wrapper for different types of `callable` validators.
+ *
+ * @author   Kubo2
+ * @since    August 2015
+ */
+final class CallableValidatorAdapter implements InputValidator {
+
+	/** @var callable */
+	private $validator;
+
+	/**
+	 * Constructs adapter's instance, taking `callable` validator as parameter.
+	 * 
+	 * @param callable $validator   The callable validator
+	 */
+	public function __construct(callable $validator) {
+		$this->validator = $validator;
+	}
+
+	/**
+	 * {@inheritdoc}
+	 * @return boolean   Anything returned by the callable validator, coerced to boolean
+	 */
+	public function validate($input) {
+		return (boolean) call_user_func($this->validator, $input);
+	}
+}