diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -14,7 +14,7 @@
 - C ← ch
 - d ← d, dd
 - e ← e, eu
-- é ← ê, é, è, ai, ei
+- E ← ê, é, è, ai, ei
 - f ← f, ff, ph
 - g ← gu
 - i ← î, i, ille
diff --git a/Sonnex.cabal b/Sonnex.cabal
--- a/Sonnex.cabal
+++ b/Sonnex.cabal
@@ -1,5 +1,5 @@
 name:                Sonnex
-version:             0.1.0.2
+version:             0.1.0.3
 synopsis:            Sonnex is an alternative to Soundex for french language
 description:
 
@@ -29,6 +29,13 @@
   hs-source-dirs:      src
   ghc-options:         -Wall
   default-language:    Haskell2010
+
+test-suite testMain
+    build-depends: QuickCheck -any, base >=4.7 && <4.8
+    type: exitcode-stdio-1.0
+    main-is: test-sonnex.hs
+    buildable: True
+    hs-source-dirs: src test
 
 source-repository head
   type: git
diff --git a/src/Text/Sonnex.hs b/src/Text/Sonnex.hs
--- a/src/Text/Sonnex.hs
+++ b/src/Text/Sonnex.hs
@@ -22,7 +22,7 @@
 - C ← ch
 - d ← d, dd
 - e ← e, eu
-- é ← ê, é, è, ai, ei
+- E ← ê, é, è, ai, ei
 - f ← f, ff, ph
 - g ← gu
 - i ← î, i, ille
@@ -92,22 +92,23 @@
 
 -- Apostroph is ignored/silent
 sonx ('\'':cs) = sonx cs
+sonx ('’':cs) = sonx cs
 
 -- Starting with 'a'
 sonx "a" = "a"
-sonx "aient" = "é"
+sonx "aient" = "E"
 sonx "ain" = "1"
 sonx ('a':'i':'n':v:cs)
-    | isVowel v = 'é':sonx (v:cs)
+    | isVowel v = 'E':sonx (v:cs)
     | otherwise = '1':sonx (v:cs)
-sonx "ais" = "é"
+sonx "ais" = "E"
 sonx ('a':'i':'s':v:cs)
-    | v == 's'  = 'é':'s':sonx cs
-    | isVowel v = 'é':'z':sonx (v:cs)
-    | otherwise = 'é':'s':sonx (v:cs)
+    | v == 's'  = 'E':'s':sonx cs
+    | isVowel v = 'E':'z':sonx (v:cs)
+    | otherwise = 'E':'s':sonx (v:cs)
 sonx "ail" = "ai"
 sonx ('a':'i':'l':'l':cs) = 'a':'i':sonx cs
-sonx ('a':'i':cs) = 'é':sonx cs
+sonx ('a':'i':cs) = 'E':sonx cs
 sonx ('a':'m':'m':cs) = 'a':'m':sonx cs
 sonx ('a':'m':c:cs)
     | c == 'm'  = 'a':'m':sonx cs
@@ -118,16 +119,19 @@
     | c == 'n'  = 'a':'n':sonx cs
     | isVowel c = 'a':'n':sonx (c:cs)
     | otherwise = '2':sonx (c:cs)
+sonx "assent" = "as"
 sonx ('a':'s':c:cs)
     | c == 's'   = 'a':'s':sonx cs
     | isConson c = 'a':'s':sonx (c:cs)
     | otherwise  = 'a':'z':sonx (c:cs)
 sonx ('a':'u':cs) = 'o':sonx cs
-sonx "ay" = "é"
-sonx "ays" = "é"
+sonx "ay" = "E"
+sonx "ays" = "E"
 
 sonx ('à':cs) = 'a':sonx cs
-sonx ('â':cs) = 'a':sonx cs
+sonx ('â':c:cs)
+    | c == 't'  = 'a':sonx ('t':cs)
+    | otherwise = 'a':sonx(c:cs)
 
 -- Starting with 'b'
 sonx "b" = ""
@@ -168,48 +172,50 @@
 
 -- Starting with 'e'
 sonx "e" = ""
-sonx "ec" = "éc"
-sonx "ef" = "éf"
+sonx "ec" = "Ec"
+sonx "ef" = "Ef"
 sonx "eaux" = "o"
 sonx ('e':'a':'n':'n':cs) = 'a':'n':sonx cs
 sonx ('e':'a':'n':cs) = '2':sonx cs
 sonx ('e':'a':'u':cs) = 'o':sonx cs
-sonx ('e':'f':'f':cs) = 'é':'f':sonx cs
+sonx ('e':'f':'f':cs) = 'E':'f':sonx cs
+sonx ('e':'g':'m':cs) = 'E':sonx ('g':'m':cs)
 sonx "ein" = "1"
 sonx ('e':'i':'n':c:cs)
-    | c == 'n'  = 'é':'n':sonx cs
-    | isVowel c = 'é':'n':sonx (c:cs)
+    | c == 'n'  = 'E':'n':sonx cs
+    | isVowel c = 'E':'n':sonx (c:cs)
     | otherwise = '1':sonx (c:cs)
-sonx ('e':'i':cs) = 'é':sonx cs
-sonx ('e':'l':'l':cs) = 'é':'l':sonx cs
+sonx ('e':'i':cs) = 'E':sonx cs
+sonx ('e':'l':'l':cs) = 'E':'l':sonx cs
 sonx ('e':'l':c:cs)
-    | isConson c = 'é':sonx ('l':c:cs)
+    | isConson c = 'E':sonx ('l':c:cs)
     | otherwise  = 'e':sonx ('l':c:cs)
-sonx ('e':'m':'m':cs) = 'é':'m':sonx cs
+sonx ('e':'m':'m':cs) = 'E':'m':sonx cs
 sonx ('e':'m':'p':cs) = '2':sonx cs
-sonx ('e':'n':'n':cs) = 'é':'n':sonx cs
+sonx ('e':'n':'n':cs) = 'E':'n':sonx cs
 sonx "en" = "2"
 sonx ('e':'n':c:cs)
     | isVowel c = 'e':'n':sonx (c:cs)
     | otherwise = '2':sonx (c:cs)
-sonx "er" = "é"
-sonx "ert" = "ér"
-sonx ('e':'r':'r':cs) = 'é':'r':sonx cs
-sonx ('e':'r':'f':cs) = 'é':'r':sonx ('f':cs)
+sonx "er" = "E"
+sonx "ert" = "Er"
+sonx ('e':'r':'r':cs) = 'E':'r':sonx cs
+sonx ('e':'r':'f':cs) = 'E':'r':sonx ('f':cs)
 sonx "es" = ""
-sonx ('e':'s':'c':'h':cs) = 'é':'C':sonx cs
+sonx ('e':'s':'c':'h':cs) = 'E':'C':sonx cs
+sonx "essent" = "Es"
 sonx ('e':'s':c:cs)
-    | c == 'h'   = 'é':sonx ('h':cs)
-    | c == 'n'   = 'é':sonx ('n':cs)
-    | c == 's'   = 'é':'s':sonx cs
-    | isConson c = 'é':'s':sonx (c:cs)
+    | c == 'h'   = 'E':sonx ('h':cs)
+    | c == 'n'   = 'E':sonx ('n':cs)
+    | c == 's'   = 'E':'s':sonx cs
+    | isConson c = 'E':'s':sonx (c:cs)
     | otherwise  = 'e':'z':sonx (c:cs)
 sonx ('é':'s':c:cs)
-    | c == 's'   = 'é':'s':sonx cs
-    | isConson c = 'é':'s':sonx (c:cs)
-    | otherwise  = 'é':'z':sonx (c:cs)
-sonx ('e':'t':'t':cs) = 'é':'t':sonx cs
-sonx "et" = "é"
+    | c == 's'   = 'E':'s':sonx cs
+    | isConson c = 'E':'s':sonx (c:cs)
+    | otherwise  = 'E':'z':sonx (c:cs)
+sonx ('e':'t':'t':cs) = 'E':'t':sonx cs
+sonx "et" = "E"
 sonx ('e':'t':cs) = 'e':'t':sonx cs
 sonx ('e':'u':'n':c:cs)
     | isVowel c = 'e':'n':sonx (c:cs)
@@ -217,23 +223,30 @@
 sonx "eux" = "e"
 sonx ('e':'u':'x':'i':cs) = 'e':'z':sonx ('i':cs)
 sonx ('e':'u':cs) = 'e':sonx cs
-sonx "ex" = "éks"
+sonx "ex" = "Eks"
 sonx ('e':'y':c:cs)
-    | isConson c = 'é':sonx (c:cs)
-    | otherwise  = 'é':sonx ('y':c:cs)
-sonx "ez" = "é"
+    | isConson c = 'E':sonx (c:cs)
+    | otherwise  = 'E':sonx ('y':c:cs)
+sonx "ez" = "E"
 
-sonx ('è':cs) = 'é':sonx cs
-sonx ('ê':cs) = 'é':sonx cs
-sonx ('ë':'l':cs) = 'é':sonx ('l':cs)
+sonx ('è':cs) = 'E':sonx cs
+sonx ('ê':c:cs)
+    | c == 't'  = 'E':sonx ('t':cs)
+    | otherwise = 'E':sonx(c:cs)
+sonx ('ë':'l':cs) = 'E':sonx ('l':cs)
+sonx "é" = "E"
+sonx ('é':c:cs)
+    | c == 't'  = 'E':'t':sonx cs
+    | otherwise = 'E':sonx(c:cs)
 
+
 -- Starting with 'f'
 sonx ('f':'f':cs) = 'f':sonx cs
 
 -- Starting with 'g'
 sonx "g" = ""
 sonx ('g':'e':cs) = 'j':sonx ('e':cs)
-sonx ('g':'é':cs) = 'j':sonx ('é':cs)
+sonx ('g':'é':cs) = 'j':sonx ('E':cs)
 sonx ('g':'i':cs) = 'j':sonx ('i':cs)
 sonx ('g':'n':cs) = 'n':sonx cs
 sonx ('g':'y':cs) = 'j':sonx ('y':cs)
@@ -247,13 +260,14 @@
 -- Starting with 'i'
 sonx "ic" = "ik"
 sonx "ics" = "ik"
-sonx ('i':'e':'n':'n':cs) = 'i':'é':'n':sonx cs
+sonx ('i':'e':'n':'n':cs) = 'i':'E':'n':sonx cs
 sonx ('i':'e':'n':cs) = 'i':'1':sonx cs
 sonx "in" = "1"
 sonx ('i':'n':c:cs)
     | c == 'n'  = 'i':'n':sonx cs
     | isVowel c = 'i':'n':sonx (c:cs)
     | otherwise = '1':sonx (c:cs)
+sonx "issent" = "is"
 sonx ('i':'s':c:cs)
     | c == 's'   = 'i':'s':sonx cs
     | isConson c = 'i':'s':sonx (c:cs)
@@ -287,6 +301,7 @@
     | otherwise = '3':sonx (c:cs)
 sonx ('o':'n':'n':cs) = 'o':'n':sonx cs
 sonx ('o':'n':cs) = '3':sonx cs
+sonx "ossent" = "os"
 sonx ('o':'s':c:cs)
     | c == 's'   = 'o':'s':sonx cs
     | isConson c = 'o':'s':sonx (c:cs)
@@ -302,7 +317,7 @@
 sonx "p" = ""
 sonx ('p':'h':cs) = 'f':sonx cs
 sonx ('p':'p':cs) = 'p':sonx cs
-sonx ('p':'a':'y':'s':cs) = 'p':'é':sonx ('i':'s':cs)
+sonx ('p':'a':'y':'s':cs) = 'p':'E':sonx ('i':'s':cs)
 
 -- Starting with 'q'
 sonx ('q':'u':'r':cs) = 'k':'u':sonx ('r':cs)
@@ -315,15 +330,19 @@
 -- Starting with 's'
 sonx "s" = ""
 sonx ('s':'s':cs) = 's':sonx cs
+sonx ('s':'t':cs) = 's':'t':sonx cs
 sonx ('s':'c':'i':cs) = 's':sonx ('i':cs)
 
 -- Starting with 't'
 sonx "t" = ""
+sonx ('t':'i':'e':'r':cs) = 't':sonx ('i':'e':'r':cs)
+sonx ('t':'i':cs) = 's':sonx ('i':cs)
 sonx ('t':'t':cs) = 't':sonx cs
 
 -- Starting with 'u'
 sonx "un" = "1"
 sonx ('û':cs) = 'u':sonx cs
+sonx "ussent" = "us"
 sonx ('u':'s':c:cs)
     | c == 's'   = 'u':'s':sonx cs
     | isConson c = 'u':'s':sonx (c:cs)
@@ -359,7 +378,24 @@
 --
 -- prop> length (sonnex w) <= length w
 sonnex :: String -> String
-sonnex = sonx . (map toLower)
+sonnex = sonnex' . map toLower
+    where sonnex' "cerf" = "sEr"
+          sonnex' "cerfs" = "sEr"
+          sonnex' "de"  = "de"
+          sonnex' "est" = "E"
+          sonnex' "es"  = "E"
+          sonnex' "huit" = "uit"
+          sonnex' "les" = "lE"
+          sonnex' "mer" = "mEr"
+          sonnex' "mes" = "mE"
+          sonnex' "ressent" = "res2"
+          sonnex' "serf" = "sEr"
+          sonnex' "serfs" = "sEr"
+          sonnex' ('s':'e':'p':'t':cs) = 's':'E':'t':sonx cs
+          sonnex' "ses" = "sE"
+          sonnex' "tes" = "tE"
+          sonnex' ('t':'i':'e':'n':cs) = 't':sonx ('i':'e':'n':cs)
+          sonnex' word = sonx word
 
 -- | Compute a Sonnex code for a french phrase.
 --
@@ -367,5 +403,5 @@
 -- Since it uses the words/unwords couple, superfluous space character
 -- are removed.
 sonnexPhrase :: String -> String
-sonnexPhrase phrase = unwords $ map sonnex (words phrase)
+sonnexPhrase = unwords . map sonnex . words
 
diff --git a/test/test-sonnex.hs b/test/test-sonnex.hs
new file mode 100644
--- /dev/null
+++ b/test/test-sonnex.hs
@@ -0,0 +1,122 @@
+{-# LANGUAGE TemplateHaskell #-}
+{-|
+Module      : TestSonnex
+Description : Tests for HaMinitel
+Copyright   : (c) Frédéric BISSON, 2014
+License     : GPL-3
+Maintainer  : zigazou@free.fr
+Stability   : alpha
+Portability : POSIX
+
+Tests for Sonnex
+-}
+
+module Main where
+
+import           Control.Monad       (unless)
+import           System.Exit         (exitFailure)
+
+import           Test.QuickCheck
+import           Test.QuickCheck.All (quickCheckAll)
+
+import           Text.Sonnex
+
+allTheSame :: (Eq a) => [a] -> Bool
+allTheSame xs = all (== head xs) (tail xs)
+
+homonymsList :: [[String]]
+homonymsList =
+    [ [ "amande", "amende"]
+    , [ "ancre", "encre" ]
+    , [ "autel", "hôtel" ]
+    , [ "balade", "ballade" ]
+    , [ "basilic", "basilique"]
+    , [ "boulot", "bouleau" ]
+    , [ "cane", "canne" ]
+    , [ "censé", "sensé" ]
+    , [ "compte", "comte", "conte" ]
+    , [ "cygne", "signe" ]
+    , [ "date", "datte" ]
+    , [ "dessin", "dessein" ]
+    , [ "différend", "différent"]
+    , [ "du", "dû" ]
+    , [ "filtre", "philtre" ]
+    , [ "flan", "flanc" ]
+    , [ "foi", "foie", "fois" ]
+    , [ "gène", "gêne" ]
+    , [ "golf", "golfe" ]
+    , [ "héraut", "héro", "héros" ]
+    , [ "lacer", "lasser" ]
+    , [ "lire", "lyre" ]
+    , [ "maire", "mer", "mère" ]
+    , [ "mal","mâle", "malle" ]
+    , [ "mite", "mythe" ]
+    , [ "pain", "pin" ]
+    , [ "palais", "palet" ]
+    , [ "a", "à" ]
+    , [ "au", "aux", "haut" ]
+    , [ "cerf", "serf", "serre" ]
+    , [ "choeur", "chœur", "cœur", "coeur" ]
+    , [ "cahos", "chaos" ]
+    , [ "ce", "se" ]
+    , [ "ai", "es", "est", "et" ]
+    , [ "cric", "crique" ]
+    , [ "on", "ont" ]
+    , [ "champ", "chant" ]
+    , [ "ou", "où" ]
+    --, [ "c'est", "s'est", "ces", "ses", "sais", "sait" ]
+    , [ "col", "colle" ]
+    --, [ "mes", "mais", "m'est", "mets", "met" ]
+    , [ "colon", "côlon" ]
+    , [ "son", "sont", "sons" ]
+    --, [ "court", "cours", "courent", "cour", "courre" ]
+    , [ "ta", "t'a", "tas" ]
+    , [ "dans", "d'en", "dent" ]
+    , [ "ma", "m'a", "m'as", "mas", "mât" ]
+    , [ "mon", "m'ont", "mont" ]
+    , [ "la", "l'a", "l'as", "là" ]
+    , [ "au", "aux", "haut" ]
+    , [ "leur", "leurs", "l'heure", "leurre" ]
+    , [ "sa", "ça", "çà" ]
+    --, [ "les", "l'ai", "l'es", "l'est", "laid", "lait", "laie" ]
+    , [ "peu", "peut", "peux" ]
+    , [ "quand", "quant", "qu'en" ]
+    , [ "ni", "n'y", "nie", "nies", "nid", "nids" ]
+    , [ "ton", "t'ont", "thon" ]
+    , [ "sans", "s'en", "sang", "cent" ]
+    , [ "tant", "temps", "tend", "tends", "t'en" ]
+    , [ "sois", "soit", "soient", "soie" ]
+    , [ "quelque", "quelques" ]
+    , [ "mur", "mûr", "mûre", "mure" ]
+    , [ "dis", "dit", "dix" ]
+    --, [ "quel", "quels", "quelle", "quelles", "qu'elle", "qu'elles" ]
+    , [ "tous", "tout", "toux" ]
+    , [ "si", "s'y", "scie" ]
+    ]
+
+prop_homonyms = forAll (elements homonymsList) $ \homonyms ->
+    allTheSame (map sonnex homonyms)
+
+tests :: [(String, String)]
+tests =
+    [ ("sept", "sEt")
+    , ("septième", "sEtiEm")
+    , ("huit", "uit")
+    , ("potion", "posi3")
+    , ("constitution", "k3stitusi3")
+    , ("chrétien", "krEti1")
+    , ("châtier", "CatiE")
+    , ("tienne", "tiEn")
+    , ("manger", "m2jE")
+    , ("siffler", "siflE")
+    , ("passionnant", "pasion2")
+    ]
+
+prop_tests = forAll (elements tests) $ \(source, result) ->
+    sonnex source == result
+
+return []
+
+main = do
+    allPass <- $quickCheckAll
+    unless allPass exitFailure