diff --git a/icartt/dataset.py b/icartt/dataset.py
index 428fc57b639c111020159c17fd7a31853fad9e37..c239874bf425cafec731c9fa6ab1fe9d26d281bd 100644
--- a/icartt/dataset.py
+++ b/icartt/dataset.py
@@ -14,7 +14,7 @@ class Variable:
 class Dataset:
     @property
     def nheader(self):
-        total = 13 + self.ndvar + self.nscom + self.nncom
+        total = 14 + self.ndvar + self.nscom + self.nncom
         if self.format == 2110:
             total += self.nauxvar + 5
         return total