diff --git a/stdnum/al/nipt.py b/stdnum/al/nipt.py
index 9091ac7e..53fc2414 100644
--- a/stdnum/al/nipt.py
+++ b/stdnum/al/nipt.py
@@ -46,7 +46,7 @@
 
 
 # regular expression for matching number
-_nipt_re = re.compile(r'^[JKL][0-9]{8}[A-Z]$')
+_nipt_re = re.compile(r'^[JKLM][0-9]{8}[A-Z]$')
 
 
 def compact(number):