diff --git a/date2name/__init__.py b/date2name/__init__.py
index e8493e7..dbe29ba 100755
--- a/date2name/__init__.py
+++ b/date2name/__init__.py
@@ -34,7 +34,7 @@ REGEX_PATTERNS = {
     'SHORT': re.compile('^(\d{2,2})([01]\d)([0123]\d)([- _])'),
     'COMPACT': re.compile('^(\d{4,4})([01]\d)([0123]\d)([- _])'),
     'STANDARD': re.compile('^(\d{4,4})-([01]\d)-([0123]\d)([- _])'),
-    'MONTH': re.compile('^(\d{4,4})-([01]\d)([- _])'),
+    'MONTH': re.compile('^(\d{4,4})-([01]\d)(?!-[0123]\d)([- _])'),
     'WITHTIME_AND_SECONDS': re.compile('^(\d{4,4})-([01]\d)-([0123]\d)([T :_-])([012]\d)([:.-])([012345]\d)([:.-])([012345]\d)([- _.])'),
     'WITHTIME_NO_SECONDS':  re.compile('^(\d{4,4})-([01]\d)-([0123]\d)([T :_-])([012]\d)([:.-])([012345]\d)([- _.])'),
     'WITHSECONDS': re.compile('^(\d{4,4})-([01]\d)-([0123]\d)([T :_-])([012]\d)([:.-])([012345]\d)([:.-])([012345]\d)([- _])'),