diff --git a/gtts/tokenizer/symbols.py b/gtts/tokenizer/symbols.py
index 1670360..17b3a62 100644
--- a/gtts/tokenizer/symbols.py
+++ b/gtts/tokenizer/symbols.py
@@ -6,7 +6,7 @@
     'prof', 'sr', 'st']
 
 SUB_PAIRS = [
-    ('M.', 'Monsieur')
+    ('Esq.', 'Esquire')
 ]
 
 ALL_PUNC = u"?!？！.,¡()[]¿…‥،;:—。，、：\n"
diff --git a/gtts/tokenizer/tests/test_pre_processors.py b/gtts/tokenizer/tests/test_pre_processors.py
index 368b9c2..8c6a428 100644
--- a/gtts/tokenizer/tests/test_pre_processors.py
+++ b/gtts/tokenizer/tests/test_pre_processors.py
@@ -21,8 +21,8 @@ def test_abbreviations(self):
         self.assertEqual(abbreviations(_in), _out)
 
     def test_word_sub(self):
-        _in = "M. Bacon"
-        _out = "Monsieur Bacon"
+        _in = "Esq. Bacon"
+        _out = "Esquire Bacon"
         self.assertEqual(word_sub(_in), _out)
 
 
diff --git a/news/197.bugfix b/news/197.bugfix
new file mode 100644
index 0000000..659e39d
--- /dev/null
+++ b/news/197.bugfix
@@ -0,0 +1 @@
+Changed default word-for-word pre-processor (``('M.', 'Monsieur')``) which would substitute any 'm.' for 'monsieur' (e.g. 'them.' became 'themonsieur')
\ No newline at end of file