diff --git a/crates/ruma-common/src/events/enums.rs b/crates/ruma-common/src/events/enums.rs
index dc83ed7d..67cdfb92 100644
--- a/crates/ruma-common/src/events/enums.rs
+++ b/crates/ruma-common/src/events/enums.rs
@@ -354,10 +354,10 @@ impl AnyMessageLikeEventContent {
             Self::Reaction(ev) => {
                 use super::reaction;
 
-                let reaction::Relation { event_id, emoji } = &ev.relates_to;
+                let reaction::Relation { event_id, key } = &ev.relates_to;
                 Some(encrypted::Relation::Annotation(encrypted::Annotation {
                     event_id: event_id.clone(),
-                    key: emoji.clone(),
+                    key: key.clone(),
                 }))
             }
             Self::RoomEncrypted(ev) => ev.relates_to.clone(),
diff --git a/crates/ruma-common/src/events/reaction.rs b/crates/ruma-common/src/events/reaction.rs
index 7627f2ce..4d26761d 100644
--- a/crates/ruma-common/src/events/reaction.rs
+++ b/crates/ruma-common/src/events/reaction.rs
@@ -32,23 +32,27 @@ impl From<Relation> for ReactionEventContent {
     }
 }
 
-/// The relation that contains info which event the reaction is applying to.
+/// Information about an annotation relation.
 #[derive(Clone, Debug, Deserialize, Serialize)]
 #[cfg_attr(not(feature = "unstable-exhaustive-types"), non_exhaustive)]
 #[serde(tag = "rel_type", rename = "m.annotation")]
 pub struct Relation {
-    /// The event that is being reacted to.
+    /// The event that is being annoted.
     pub event_id: Box<EventId>,
 
-    /// A string that holds the emoji reaction.
-    #[serde(rename = "key")]
-    pub emoji: String,
+    /// A string that indicates the annotation being applied.
+    ///
+    /// When sending emoji reactions, this field should include the colourful variation-16 when
+    /// applicable.
+    ///
+    /// Clients should render reactions that have a long `key` field in a sensible manner.
+    pub key: String,
 }
 
 impl Relation {
-    /// Creates a new `Relation` with the given event ID and emoji.
-    pub fn new(event_id: Box<EventId>, emoji: String) -> Self {
-        Self { event_id, emoji }
+    /// Creates a new `Relation` with the given event ID and key.
+    pub fn new(event_id: Box<EventId>, key: String) -> Self {
+        Self { event_id, key }
     }
 }
 
@@ -74,8 +78,8 @@ mod tests {
 
         assert_matches!(
             from_json_value::<ReactionEventContent>(json).unwrap(),
-            ReactionEventContent { relates_to: Relation { event_id, emoji } }
-            if event_id == ev_id && emoji == "🦛"
+            ReactionEventContent { relates_to: Relation { event_id, key } }
+            if event_id == ev_id && key == "🦛"
         );
     }
 }
diff --git a/crates/ruma-common/src/events/relation.rs b/crates/ruma-common/src/events/relation.rs
index 519e6dea..5fa05e95 100644
--- a/crates/ruma-common/src/events/relation.rs
+++ b/crates/ruma-common/src/events/relation.rs
@@ -12,7 +12,7 @@ use crate::{EventId, MilliSecondsSinceUnixEpoch, UserId};
 #[cfg(feature = "unstable-msc2677")]
 #[cfg_attr(not(feature = "unstable-exhaustive-types"), non_exhaustive)]
 pub struct BundledReaction {
-    /// The key (emoji) used for reaction.
+    /// The key used for the reaction.
     pub key: String,
 
     /// Time of the bundled reaction being compiled on the server.