diff --git a/lib/yaml/resolver.py b/lib/yaml/resolver.py
index f49eda6..6062406 100644
--- a/lib/yaml/resolver.py
+++ b/lib/yaml/resolver.py
@@ -153,7 +153,7 @@ class Resolver(BaseResolver):
 
 Resolver.add_implicit_resolver(
         u'tag:yaml.org,2002:bool',
-        re.compile(ur'''^(?:yes|Yes|YES|n|N|no|No|NO
+        re.compile(ur'''^(?:yes|Yes|YES|no|No|NO
                     |true|True|TRUE|false|False|FALSE
                     |on|On|ON|off|Off|OFF)$''', re.X),
         list(u'yYnNtTfFoO'))
diff --git a/tests/data/construct-bool.code b/tests/data/construct-bool.code
index 389d2c0..3d02580 100644
--- a/tests/data/construct-bool.code
+++ b/tests/data/construct-bool.code
@@ -3,4 +3,5 @@
     "answer": False,
     "logical": True,
     "option": True,
+    "but": { "y": "is a string", "n": "is a string" },
 }
diff --git a/tests/data/construct-bool.data b/tests/data/construct-bool.data
index e751222..36d6519 100644
--- a/tests/data/construct-bool.data
+++ b/tests/data/construct-bool.data
@@ -2,3 +2,8 @@ canonical: yes
 answer: NO
 logical: True
 option: on
+
+
+but:
+    y: is a string
+    n: is a string