diff --git a/src/client/data/caps.rs b/src/client/data/caps.rs
index e4ab055..6ef75ef 100644
--- a/src/client/data/caps.rs
+++ b/src/client/data/caps.rs
@@ -30,6 +30,8 @@ pub enum Capability {
     UserhostInNames,
     /// [metadata](http://ircv3.net/specs/core/metadata-3.2.html)
     Metadata,
+    /// [metadata-notify](http://ircv3.net/specs/core/metadata-3.2.html)
+    MetadataNotify,
     /// Custom IRCv3 capability extensions
     Custom(&'static str),
 }
@@ -58,6 +60,7 @@ impl AsRef<str> for Capability {
             Capability::ServerTime => "server-time",
             Capability::UserhostInNames => "userhost-in-names",
             Capability::Metadata => "metadata",
+            Capability::MetadataNotify => "metadata-notify",
             Capability::Custom(s) => s,
         }
     }
@@ -82,6 +85,7 @@ mod test {
         assert_eq!(ServerTime.as_ref(), "server-time");
         assert_eq!(UserhostInNames.as_ref(), "userhost-in-names");
         assert_eq!(Metadata.as_ref(), "metadata");
+        assert_eq!(MetadataNotify.as_ref(), "metadata-notify");
         assert_eq!(Custom("example").as_ref(), "example");
     }
 }
diff --git a/src/client/data/command.rs b/src/client/data/command.rs
index c50ea85..f36d4a8 100644
--- a/src/client/data/command.rs
+++ b/src/client/data/command.rs
@@ -158,7 +158,7 @@ pub enum Command {
 
     // IRCv3.2 extensions
     /// METADATA target COMMAND [params] :[param]
-    METADATA(String, MetadataSubCommand, Option<Vec<String>>, Option<String>),
+    METADATA(String, Option<MetadataSubCommand>, Option<Vec<String>>, Option<String>),
     /// MONITOR command [nicklist]
     MONITOR(String, Option<String>),
     /// CHGHOST user host
@@ -335,11 +335,16 @@ impl Into<Message> for Command {
             Command::ACCOUNT(a) =>
                 Message::from_owned(None, string("ACCOUNT"), Some(vec![a]), None),
 
-            Command::METADATA(t, c, None, p) =>
+            Command::METADATA(t, Some(c), None, p) =>
                 Message::from_owned(None, string("METADATA"), Some(vec![t, c.string()]), p),
-            Command::METADATA(t, c, Some(a), p) =>
+            Command::METADATA(t, Some(c), Some(a), p) =>
                 Message::from_owned(None, string("METADATA"),
                                     Some(vec![t, c.string()].into_iter().chain(a).collect()), p),
+            Command::METADATA(t, None, None, p) =>
+                Message::from_owned(None, string("METADATA"), Some(vec![t]), p),
+            Command::METADATA(t, None, Some(a), p) =>
+                Message::from_owned(None, string("METADATA"),
+                                    Some(vec![t].into_iter().chain(a).collect()), p),
             Command::MONITOR(c, Some(t)) =>
                 Message::from_owned(None, string("MONITOR"), Some(vec![c, t]), None),
             Command::MONITOR(c, None) =>
@@ -1097,15 +1102,19 @@ impl<'a> From<&'a Message> for Result<Command> {
                 match m.suffix {
                     Some(_) => return Err(invalid_input()),
                     None => match m.args[1].parse() {
-                        Ok(c) => Command::METADATA(m.args[0].clone(), c, None, None),
+                        Ok(c) => Command::METADATA(m.args[0].clone(), Some(c), None, None),
                         Err(_) => return Err(invalid_input()),
                     },
                 }
             } else if m.args.len() > 2 {
                 match m.args[1].parse() {
-                    Ok(c) => Command::METADATA(m.args[0].clone(), c, Some(m.args[1..].to_owned()),
-                                                 m.suffix.clone()),
-                    Err(_) => return Err(invalid_input()),
+                    Ok(c) => Command::METADATA(m.args[0].clone(), Some(c),
+                                               Some(m.args[1..].to_owned()), m.suffix.clone()),
+                    Err(_) => if m.args.len() == 3 && m.suffix.is_some() {
+                        Command::METADATA(m.args[0].clone(), None, Some(m.args[1..].to_owned()), m.suffix.clone())
+                    } else {
+                        return Err(invalid_input())
+                    },
                 }
             } else {
                 return Err(invalid_input())