diff --git a/cake/libs/model/model.php b/cake/libs/model/model.php
index 060e3bc016c..854759adf51 100644
--- a/cake/libs/model/model.php
+++ b/cake/libs/model/model.php
@@ -2547,6 +2547,13 @@ function invalidFields($options = array()) {
 							$valid = $Validation->dispatchMethod($rule, $ruleParams);
 						} elseif (!is_array($validator['rule'])) {
 							$valid = preg_match($rule, $data[$fieldName]);
+						} elseif (Configure::read('debug') > 0) {
+							$error = sprintf(
+								__('Could not find validation handler %s for %s', true), 
+								$rule,
+								$fieldName
+							);
+							trigger_error($error, E_USER_WARNING);
 						}
 
 						if (!$valid || (is_string($valid) && strlen($valid) > 0)) {
diff --git a/cake/tests/cases/libs/model/model_validation.test.php b/cake/tests/cases/libs/model/model_validation.test.php
index 94a3815028d..0fbc2b63fff 100644
--- a/cake/tests/cases/libs/model/model_validation.test.php
+++ b/cake/tests/cases/libs/model/model_validation.test.php
@@ -126,5 +126,32 @@ function testInvalidFieldsWithFieldListParams() {
 		$this->assertEqual($TestModel->validate, $validate);
 	}
 
+/**
+ * Test that missing validation methods trigger errors in development mode.
+ * Helps to make developement easier.
+ *
+ * @return void
+ **/
+	function testMissingValidationErrorTriggering() {
+		$restore = Configure::read('debug');
+		Configure::write('debug', 2);
+
+		$TestModel =& new ValidationTest1();
+		$TestModel->create(array('title' => 'foo'));
+		$TestModel->validate = array(
+			'title' => array(
+				'rule' => array('thisOneBringsThePain'),
+				'required' => true
+			)
+		);
+		$this->expectError(new PatternExpectation('/thisOneBringsThePain for title/i'));
+		$TestModel->invalidFields(array('fieldList' => array('title')));
+
+		Configure::write('debug', 0);
+		$this->assertNoErrors();
+		$TestModel->invalidFields(array('fieldList' => array('title')));
+		Configure::write('debug', $restore);
+	}
+
 }
 ?>
\ No newline at end of file