diff --git a/lib/g3-dpi/src/protocol/ftp.rs b/lib/g3-dpi/src/protocol/ftp.rs
index 262a41b74..25d25b9ea 100644
--- a/lib/g3-dpi/src/protocol/ftp.rs
+++ b/lib/g3-dpi/src/protocol/ftp.rs
@@ -40,6 +40,7 @@ impl ProtocolInspectState {
                 self.exclude_other(MaybeProtocol::Smtp);
                 self.exclude_other(MaybeProtocol::Odmr);
                 self.exclude_other(MaybeProtocol::Nntp);
+                self.exclude_other(MaybeProtocol::Nnsp);
 
                 if &data[0..3] == b"120" {
                     return self.check_ftp_after_code(data, size_limit);
@@ -54,6 +55,7 @@ impl ProtocolInspectState {
                     return Ok(None);
                 }
                 self.exclude_other(MaybeProtocol::Nntp);
+                self.exclude_other(MaybeProtocol::Nnsp);
 
                 if data[2] == b'0' {
                     // may be SMTP
@@ -66,6 +68,7 @@ impl ProtocolInspectState {
                 self.exclude_other(MaybeProtocol::Smtp);
                 self.exclude_other(MaybeProtocol::Odmr);
                 self.exclude_other(MaybeProtocol::Nntp);
+                self.exclude_other(MaybeProtocol::Nnsp);
 
                 if &data[0..3] == b"421" {
                     return self.check_ftp_after_code(data, size_limit);
diff --git a/lib/g3-dpi/src/protocol/imap.rs b/lib/g3-dpi/src/protocol/imap.rs
index 2c15b62aa..c6c4e3920 100644
--- a/lib/g3-dpi/src/protocol/imap.rs
+++ b/lib/g3-dpi/src/protocol/imap.rs
@@ -46,6 +46,7 @@ impl ProtocolInspectState {
         self.exclude_other(MaybeProtocol::Odmr);
         self.exclude_other(MaybeProtocol::Pop3);
         self.exclude_other(MaybeProtocol::Nntp);
+        self.exclude_other(MaybeProtocol::Nnsp);
         self.exclude_other(MaybeProtocol::Nats);
         self.exclude_other(MaybeProtocol::BitTorrent);
 
diff --git a/lib/g3-dpi/src/protocol/nats.rs b/lib/g3-dpi/src/protocol/nats.rs
index 96a05812c..ca218e40a 100644
--- a/lib/g3-dpi/src/protocol/nats.rs
+++ b/lib/g3-dpi/src/protocol/nats.rs
@@ -45,6 +45,7 @@ impl ProtocolInspectState {
         self.exclude_other(MaybeProtocol::Odmr);
         self.exclude_other(MaybeProtocol::Pop3);
         self.exclude_other(MaybeProtocol::Nntp);
+        self.exclude_other(MaybeProtocol::Nnsp);
         self.exclude_other(MaybeProtocol::Imap);
         self.exclude_other(MaybeProtocol::BitTorrent);
 
diff --git a/lib/g3-dpi/src/protocol/nntp.rs b/lib/g3-dpi/src/protocol/nntp.rs
index dd59d5f3c..317433738 100644
--- a/lib/g3-dpi/src/protocol/nntp.rs
+++ b/lib/g3-dpi/src/protocol/nntp.rs
@@ -45,6 +45,7 @@ impl ProtocolInspectState {
         // exclude impossible protocols
         self.exclude_other(MaybeProtocol::Ssh);
         self.exclude_other(MaybeProtocol::Nntp);
+        self.exclude_other(MaybeProtocol::Nnsp);
         self.exclude_other(MaybeProtocol::Imap);
         self.exclude_other(MaybeProtocol::Nats);
         self.exclude_other(MaybeProtocol::BitTorrent);
diff --git a/lib/g3-dpi/src/protocol/pop3.rs b/lib/g3-dpi/src/protocol/pop3.rs
index b8cd00dc9..d1c11508b 100644
--- a/lib/g3-dpi/src/protocol/pop3.rs
+++ b/lib/g3-dpi/src/protocol/pop3.rs
@@ -48,6 +48,7 @@ impl ProtocolInspectState {
         self.exclude_other(MaybeProtocol::Smtp);
         self.exclude_other(MaybeProtocol::Odmr);
         self.exclude_other(MaybeProtocol::Nntp);
+        self.exclude_other(MaybeProtocol::Nnsp);
         self.exclude_other(MaybeProtocol::Imap);
         self.exclude_other(MaybeProtocol::Nats);
         self.exclude_other(MaybeProtocol::BitTorrent);
diff --git a/lib/g3-dpi/src/protocol/smtp.rs b/lib/g3-dpi/src/protocol/smtp.rs
index 5959232c9..1518810a9 100644
--- a/lib/g3-dpi/src/protocol/smtp.rs
+++ b/lib/g3-dpi/src/protocol/smtp.rs
@@ -45,6 +45,7 @@ impl ProtocolInspectState {
                     return Ok(None);
                 }
                 self.exclude_other(MaybeProtocol::Nntp);
+                self.exclude_other(MaybeProtocol::Nnsp);
 
                 if data[2] == b'0' {
                     // may be FTP
@@ -56,6 +57,7 @@ impl ProtocolInspectState {
                 self.smtp_exclude_by_byte0();
                 self.exclude_other(MaybeProtocol::Ftp);
                 self.exclude_other(MaybeProtocol::Nntp);
+                self.exclude_other(MaybeProtocol::Nnsp);
 
                 if &data[0..3] == b"554" {
                     return self.check_smtp_after_code(data);
diff --git a/lib/g3-dpi/src/protocol/ssh.rs b/lib/g3-dpi/src/protocol/ssh.rs
index ed8705a0d..a8d0fc218 100644
--- a/lib/g3-dpi/src/protocol/ssh.rs
+++ b/lib/g3-dpi/src/protocol/ssh.rs
@@ -121,6 +121,7 @@ impl ProtocolInspectState {
         self.exclude_other(MaybeProtocol::Odmr);
         self.exclude_other(MaybeProtocol::Pop3);
         self.exclude_other(MaybeProtocol::Nntp);
+        self.exclude_other(MaybeProtocol::Nnsp);
         self.exclude_other(MaybeProtocol::Imap);
         self.exclude_other(MaybeProtocol::Nats);
         self.exclude_other(MaybeProtocol::BitTorrent);