diff --git a/lib/Cake/Test/Case/Utility/InflectorTest.php b/lib/Cake/Test/Case/Utility/InflectorTest.php
index caf085ad1..343215098 100644
--- a/lib/Cake/Test/Case/Utility/InflectorTest.php
+++ b/lib/Cake/Test/Case/Utility/InflectorTest.php
@@ -123,6 +123,7 @@ class InflectorTest extends CakeTestCase {
 		$this->assertEquals(Inflector::singularize('fungi'), 'fungus');
 		$this->assertEquals(Inflector::singularize('nuclei'), 'nucleus');
 		$this->assertEquals(Inflector::singularize('octopuses'), 'octopus');
+		$this->assertEquals(Inflector::singularize('octopuses'), 'octopus');
 		$this->assertEquals(Inflector::singularize('radii'), 'radius');
 		$this->assertEquals(Inflector::singularize('stimuli'), 'stimulus');
 		$this->assertEquals(Inflector::singularize('syllabi'), 'syllabus');
@@ -178,6 +179,7 @@ class InflectorTest extends CakeTestCase {
 		$this->assertEquals(Inflector::singularize('metadata'), 'metadata');
 		$this->assertEquals(Inflector::singularize('files_metadata'), 'files_metadata');
 		$this->assertEquals(Inflector::singularize('sieves'), 'sieve');
+		$this->assertEquals(Inflector::singularize('blue_octopuses'), 'blue_octopus');
 		$this->assertEquals(Inflector::singularize(''), '');
 	}
 
@@ -250,6 +252,7 @@ class InflectorTest extends CakeTestCase {
 		$this->assertEquals(Inflector::pluralize('files_metadata'), 'files_metadata');
 		$this->assertEquals(Inflector::pluralize('stadia'), 'stadia');
 		$this->assertEquals(Inflector::pluralize('sieve'), 'sieves');
+		$this->assertEquals(Inflector::pluralize('blue_octopus'), 'blue_octopuses');
 		$this->assertEquals(Inflector::pluralize(''), '');
 	}
 
diff --git a/lib/Cake/Utility/Inflector.php b/lib/Cake/Utility/Inflector.php
index 33e4ecf1c..0d245c517 100644
--- a/lib/Cake/Utility/Inflector.php
+++ b/lib/Cake/Utility/Inflector.php
@@ -387,7 +387,7 @@ class Inflector {
 		}
 
 		if (preg_match('/(.*)\\b(' . self::$_plural['cacheIrregular'] . ')$/i', $word, $regs)) {
-			self::$_cache['pluralize'][$word] = $regs[1] . substr($word, 0, 1) . substr(self::$_plural['merged']['irregular'][strtolower($regs[2])], 1);
+			self::$_cache['pluralize'][$word] = $regs[1] . substr($regs[2], 0, 1) . substr(self::$_plural['merged']['irregular'][strtolower($regs[2])], 1);
 			return self::$_cache['pluralize'][$word];
 		}
 
@@ -436,7 +436,7 @@ class Inflector {
 		}
 
 		if (preg_match('/(.*)\\b(' . self::$_singular['cacheIrregular'] . ')$/i', $word, $regs)) {
-			self::$_cache['singularize'][$word] = $regs[1] . substr($word, 0, 1) . substr(self::$_singular['merged']['irregular'][strtolower($regs[2])], 1);
+			self::$_cache['singularize'][$word] = $regs[1] . substr($regs[2], 0, 1) . substr(self::$_singular['merged']['irregular'][strtolower($regs[2])], 1);
 			return self::$_cache['singularize'][$word];
 		}