diff --git a/doc/configuration.txt b/doc/configuration.txt
index da108abd9..cb4cd44b1 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -15630,7 +15630,7 @@ fix_is_valid
     numeric
   - checks the BeginString tag is the first tag with a valid FIX version
   - checks the BodyLength tag is the second one with the right body length
-  - checks the MstType tag is the third tag.
+  - checks the MsgType tag is the third tag.
   - checks that last tag in the message is the CheckSum tag with a valid
     checksum