diff --git a/crates/ruma-events/src/room/message/audio.rs b/crates/ruma-events/src/room/message/audio.rs
index 4ee49ede..c9c9a237 100644
--- a/crates/ruma-events/src/room/message/audio.rs
+++ b/crates/ruma-events/src/room/message/audio.rs
@@ -18,7 +18,9 @@ pub struct AudioMessageEventContent {
     /// uploaded file. Otherwise, this should be interpreted as a user-written media caption.
     pub body: String,
 
-    /// Formatted form of the message `body`, if `body` is a caption.
+    /// Formatted form of the message `body`.
+    ///
+    /// This should only be set if the body represents a caption.
     #[serde(flatten)]
     pub formatted: Option<FormattedBody>,
 
diff --git a/crates/ruma-events/src/room/message/file.rs b/crates/ruma-events/src/room/message/file.rs
index aaca269e..8601bd1a 100644
--- a/crates/ruma-events/src/room/message/file.rs
+++ b/crates/ruma-events/src/room/message/file.rs
@@ -16,7 +16,9 @@ pub struct FileMessageEventContent {
     /// uploaded file. Otherwise, this should be interpreted as a user-written media caption.
     pub body: String,
 
-    /// Formatted form of the message `body`, if `body` is a caption.
+    /// Formatted form of the message `body`.
+    ///
+    /// This should only be set if the body represents a caption.
     #[serde(flatten)]
     pub formatted: Option<FormattedBody>,
 
diff --git a/crates/ruma-events/src/room/message/image.rs b/crates/ruma-events/src/room/message/image.rs
index 8c7336d2..55c33401 100644
--- a/crates/ruma-events/src/room/message/image.rs
+++ b/crates/ruma-events/src/room/message/image.rs
@@ -15,7 +15,9 @@ pub struct ImageMessageEventContent {
     /// uploaded file. Otherwise, this should be interpreted as a user-written media caption.
     pub body: String,
 
-    /// Formatted form of the message `body`, if `body` is a caption.
+    /// Formatted form of the message `body`.
+    ///
+    /// This should only be set if the body represents a caption.
     #[serde(flatten)]
     pub formatted: Option<FormattedBody>,
 
diff --git a/crates/ruma-events/src/room/message/video.rs b/crates/ruma-events/src/room/message/video.rs
index 428e9f04..30fd9d55 100644
--- a/crates/ruma-events/src/room/message/video.rs
+++ b/crates/ruma-events/src/room/message/video.rs
@@ -18,7 +18,9 @@ pub struct VideoMessageEventContent {
     /// uploaded file. Otherwise, this should be interpreted as a user-written media caption.
     pub body: String,
 
-    /// Formatted form of the message `body`, if `body` is a caption.
+    /// Formatted form of the message `body`.
+    ///
+    /// This should only be set if the body represents a caption.
     #[serde(flatten)]
     pub formatted: Option<FormattedBody>,