diff --git a/src/client/data/caps.rs b/src/client/data/caps.rs
index 5507ff2..2ee55b3 100644
--- a/src/client/data/caps.rs
+++ b/src/client/data/caps.rs
@@ -16,6 +16,8 @@ pub enum Capability {
     Monitor,
     /// [account-tag](http://ircv3.net/specs/extensions/account-tag-3.2.html)
     AccountTag,
+    /// [cap-notify](http://ircv3.net/specs/extensions/cap-notify-3.2.html)
+    CapNotify,
 }
 
 /// List of IRCv3 capability negotiation versions.
@@ -35,6 +37,7 @@ impl AsRef<str> for Capability {
             Capability::ExtendedJoin => "extended-join",
             Capability::Monitor => "monitor",
             Capability::AccountTag => "account-tag",
+            Capability::CapNotify => "cap-notify",
         }
     }
 }
@@ -51,5 +54,6 @@ mod test {
         assert_eq!(ExtendedJoin.as_ref(), "extended-join");
         assert_eq!(Monitor.as_ref(), "monitor");
         assert_eq!(AccountTag.as_ref(), "account-tag");
+        assert_eq!(CapNotify.as_ref(), "cap-notify");
     }
 }
diff --git a/src/client/data/command.rs b/src/client/data/command.rs
index 731cb49..483661e 100644
--- a/src/client/data/command.rs
+++ b/src/client/data/command.rs
@@ -1106,7 +1106,11 @@ pub enum CapSubCommand {
     /// Does not acknowledge certain capabilities.
     NAK,
     /// Ends the capability negotiation before registration.
-    END
+    END,
+    /// Signals that new capabilities are now being offered.
+    NEW,
+    /// Signasl that the specified capabilities are cancelled and no longer available.
+    DEL,
 }
 
 impl CapSubCommand {
@@ -1119,6 +1123,8 @@ impl CapSubCommand {
             &CapSubCommand::ACK   => "ACK",
             &CapSubCommand::NAK   => "NAK",
             &CapSubCommand::END   => "END",
+            &CapSubCommand::NEW   => "NEW",
+            &CapSubCommand::DEL   => "DEL",
         }
     }
 
@@ -1138,6 +1144,8 @@ impl FromStr for CapSubCommand {
             "ACK"   => Ok(CapSubCommand::ACK),
             "NAK"   => Ok(CapSubCommand::NAK),
             "END"   => Ok(CapSubCommand::END),
+            "NEW"   => Ok(CapSubCommand::NEW),
+            "DEL"   => Ok(CapSubCommand::DEL),
             _       => Err("Failed to parse CAP subcommand."),
         }
     }