diff --git a/src/Symfony/Component/Inflector/Inflector.php b/src/Symfony/Component/Inflector/Inflector.php
index 15198293cf..58399b6322 100644
--- a/src/Symfony/Component/Inflector/Inflector.php
+++ b/src/Symfony/Component/Inflector/Inflector.php
@@ -228,6 +228,9 @@ final class Inflector
         // bacteria (bacterium), criteria (criterion), phenomena (phenomenon)
         ['noi', 3, true, true, 'ions'],
 
+        // seasons (season), treasons (treason), poisons (poison), lessons (lesson)
+        ['nos', 3, true, true, 'sons'],
+
         // bacteria (bacterium), criteria (criterion), phenomena (phenomenon)
         ['no', 2, true, true, 'a'],
 
diff --git a/src/Symfony/Component/Inflector/Tests/InflectorTest.php b/src/Symfony/Component/Inflector/Tests/InflectorTest.php
index 1178edf35b..38df846ba6 100644
--- a/src/Symfony/Component/Inflector/Tests/InflectorTest.php
+++ b/src/Symfony/Component/Inflector/Tests/InflectorTest.php
@@ -93,6 +93,7 @@ class InflectorTest extends TestCase
             ['kisses', 'kiss'],
             ['knives', 'knife'],
             ['lamps', 'lamp'],
+            ['lessons', 'lesson'],
             ['leaves', ['leaf', 'leave', 'leaff']],
             ['lice', 'louse'],
             ['lives', 'life'],
@@ -115,6 +116,7 @@ class InflectorTest extends TestCase
             ['photos', 'photo'],
             ['pianos', 'piano'],
             ['plateaux', 'plateau'],
+            ['poisons', 'poison'],
             ['poppies', 'poppy'],
             ['prices', ['prex', 'prix', 'price']],
             ['quizzes', 'quiz'],
@@ -124,6 +126,7 @@ class InflectorTest extends TestCase
             ['sandwiches', ['sandwich', 'sandwiche']],
             ['scarves', ['scarf', 'scarve', 'scarff']],
             ['schemas', 'schema'], //schemata
+            ['seasons', 'season'],
             ['selfies', 'selfie'],
             ['series', 'series'],
             ['services', 'service'],
@@ -139,6 +142,7 @@ class InflectorTest extends TestCase
             ['teeth', 'tooth'],
             ['theses', ['thes', 'these', 'thesis']],
             ['thieves', ['thief', 'thieve', 'thieff']],
+            ['treasons', 'treason'],
             ['trees', ['tre', 'tree']],
             ['waltzes', ['waltz', 'waltze']],
             ['wives', 'wife'],
@@ -226,6 +230,7 @@ class InflectorTest extends TestCase
             ['knife', 'knives'],
             ['lamp', 'lamps'],
             ['leaf', ['leafs', 'leaves']],
+            ['lesson', 'lessons'],
             ['life', 'lives'],
             ['louse', 'lice'],
             ['man', 'men'],
@@ -245,6 +250,7 @@ class InflectorTest extends TestCase
             ['photo', 'photos'],
             ['piano', 'pianos'],
             ['plateau', ['plateaus', 'plateaux']],
+            ['poison', 'poisons'],
             ['poppy', 'poppies'],
             ['price', 'prices'],
             ['quiz', 'quizzes'],
@@ -254,6 +260,7 @@ class InflectorTest extends TestCase
             ['sandwich', 'sandwiches'],
             ['scarf', ['scarfs', 'scarves']],
             ['schema', 'schemas'], //schemata
+            ['season', 'seasons'],
             ['selfie', 'selfies'],
             ['series', 'series'],
             ['service', 'services'],
@@ -268,6 +275,7 @@ class InflectorTest extends TestCase
             ['tag', 'tags'],
             ['thief', ['thiefs', 'thieves']],
             ['tooth', 'teeth'],
+            ['treason', 'treasons'],
             ['tree', 'trees'],
             ['waltz', 'waltzes'],
             ['wife', 'wives'],