diff --git a/nmap-service-probes b/nmap-service-probes
index 3fd78a504..0a4c46057 100644
--- a/nmap-service-probes
+++ b/nmap-service-probes
@@ -3265,7 +3265,7 @@ match clam m|^UNKNOWN COMMAND\n$| p/Clam AV/
 match cmae m|^_err=refused%20by%20workers\r\n$| p/Cloudmark cmae_server antispam/
 match conserver m|^ok\r\nunknown command\r\nunknown command\r\n$| p/conserver serial console daemon/ d/specialized/
 
-match ccso m|^598:\(null\):Command not recognized\.\n| p/Columbia University QIL Gateway/ i/Qi to LDAP/
+match cso m|^598:\(null\):Command not recognized\.\n| p/Columbia University QIL Gateway/ i/Qi to LDAP/
 
 match datamaxdb m|^X01\r\nX01\r\n$| p/MailMax DataMaxDB/ o/Windows/