diff --git a/ruma-events-macros/src/gen.rs b/ruma-events-macros/src/gen.rs
index fe1b6ac9..9a5c587f 100644
--- a/ruma-events-macros/src/gen.rs
+++ b/ruma-events-macros/src/gen.rs
@@ -154,8 +154,8 @@ impl ToTokens for RumaEvent {
                         }
 
                         /// Additional key-value pairs not signed by the homeserver.
-                        fn unsigned(&self) -> Option<&serde_json::Value> {
-                            self.unsigned.as_ref()
+                        fn unsigned(&self) -> &serde_json::Map<String, serde_json::Value> {
+                            &self.unsigned
                         }
                     }
                 }
@@ -296,8 +296,8 @@ fn populate_room_event_fields(content_name: Ident, fields: Vec<Field>) -> Vec<Fi
         pub sender: ruma_identifiers::UserId,
 
         /// Additional key-value pairs not signed by the homeserver.
-        #[serde(skip_serializing_if = "Option::is_none")]
-        pub unsigned: Option<serde_json::Value>,
+        #[serde(default, skip_serializing_if = "serde_json::Map::is_empty")]
+        pub unsigned: serde_json::Map<String, serde_json::Value>,
     };
 
     fields.extend(punctuated_fields.into_iter().map(|p| p.field));
diff --git a/src/lib.rs b/src/lib.rs
index 9a4b6e5a..1219f392 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -126,7 +126,7 @@ use serde::{
     ser::SerializeMap,
     Deserialize, Deserializer, Serialize, Serializer,
 };
-use serde_json::Value;
+use serde_json::{Map, Value};
 
 pub use self::{custom::CustomEvent, custom_room::CustomRoomEvent, custom_state::CustomStateEvent};
 
@@ -394,7 +394,7 @@ pub trait RoomEvent: Event {
     fn sender(&self) -> &UserId;
 
     /// Additional key-value pairs not signed by the homeserver.
-    fn unsigned(&self) -> Option<&Value>;
+    fn unsigned(&self) -> &Map<String, Value>;
 }
 
 /// An event that describes persistent state about a room.
@@ -461,7 +461,7 @@ mod custom_room {
 
     use ruma_events_macros::FromRaw;
     use serde::{Deserialize, Serialize};
-    use serde_json::Value;
+    use serde_json::{Map, Value};
 
     /// A custom room event not covered by the Matrix specification.
     #[derive(Clone, Debug, FromRaw, PartialEq, Serialize)]
@@ -481,7 +481,8 @@ mod custom_room {
         /// The unique identifier for the user who sent this event.
         pub sender: ruma_identifiers::UserId,
         /// Additional key-value pairs not signed by the homeserver.
-        pub unsigned: Option<serde_json::Value>,
+        #[serde(skip_serializing_if = "serde_json::Map::is_empty")]
+        pub unsigned: Map<String, Value>,
     }
 
     /// The payload for `CustomRoomEvent`.
@@ -522,8 +523,8 @@ mod custom_room {
             &self.sender
         }
         /// Additional key-value pairs not signed by the homeserver.
-        fn unsigned(&self) -> Option<&serde_json::Value> {
-            self.unsigned.as_ref()
+        fn unsigned(&self) -> &Map<String, Value> {
+            &self.unsigned
         }
     }
 
@@ -548,7 +549,8 @@ mod custom_room {
             /// The unique identifier for the user who sent this event.
             pub sender: ruma_identifiers::UserId,
             /// Additional key-value pairs not signed by the homeserver.
-            pub unsigned: Option<serde_json::Value>,
+            #[serde(default)]
+            pub unsigned: Map<String, Value>,
         }
     }
 }
@@ -558,7 +560,7 @@ mod custom_state {
 
     use ruma_events_macros::FromRaw;
     use serde::{Deserialize, Serialize};
-    use serde_json::Value;
+    use serde_json::{Map, Value};
 
     /// A custom state event not covered by the Matrix specification.
     #[derive(Clone, Debug, FromRaw, PartialEq, Serialize)]
@@ -582,7 +584,8 @@ mod custom_state {
         /// A key that determines which piece of room state the event represents.
         pub state_key: String,
         /// Additional key-value pairs not signed by the homeserver.
-        pub unsigned: Option<serde_json::Value>,
+        #[serde(skip_serializing_if = "serde_json::Map::is_empty")]
+        pub unsigned: Map<String, Value>,
     }
 
     /// The payload for `CustomStateEvent`.
@@ -623,8 +626,8 @@ mod custom_state {
             &self.sender
         }
         /// Additional key-value pairs not signed by the homeserver.
-        fn unsigned(&self) -> Option<&serde_json::Value> {
-            self.unsigned.as_ref()
+        fn unsigned(&self) -> &Map<String, Value> {
+            &self.unsigned
         }
     }
 
@@ -664,7 +667,8 @@ mod custom_state {
             /// A key that determines which piece of room state the event represents.
             pub state_key: String,
             /// Additional key-value pairs not signed by the homeserver.
-            pub unsigned: Option<serde_json::Value>,
+            #[serde(default)]
+            pub unsigned: Map<String, Value>,
         }
     }
 }
diff --git a/src/macros.rs b/src/macros.rs
index 91838a4a..b2bb7bbb 100644
--- a/src/macros.rs
+++ b/src/macros.rs
@@ -73,8 +73,8 @@ macro_rules! impl_room_event {
             }
 
             /// Additional key-value pairs not signed by the homeserver.
-            fn unsigned(&self) -> Option<&Value> {
-                self.unsigned.as_ref()
+            fn unsigned(&self) -> &serde_json::Map<String, serde_json::Value> {
+                &self.unsigned
             }
         }
     };
diff --git a/src/room/canonical_alias.rs b/src/room/canonical_alias.rs
index 42208cc1..66580066 100644
--- a/src/room/canonical_alias.rs
+++ b/src/room/canonical_alias.rs
@@ -3,7 +3,7 @@
 use js_int::UInt;
 use ruma_identifiers::{EventId, RoomAliasId, RoomId, UserId};
 use serde::{ser::SerializeStruct, Deserialize, Serialize, Serializer};
-use serde_json::Value;
+use serde_json::{Map, Value};
 
 use crate::{util::empty_string_as_none, Event, EventType, FromRaw};
 
@@ -33,7 +33,7 @@ pub struct CanonicalAliasEvent {
     pub state_key: String,
 
     /// Additional key-value pairs not signed by the homeserver.
-    pub unsigned: Option<Value>,
+    pub unsigned: Map<String, Value>,
 }
 
 /// The payload for `CanonicalAliasEvent`.
@@ -85,7 +85,7 @@ impl Serialize for CanonicalAliasEvent {
             len += 1;
         }
 
-        if self.unsigned.is_some() {
+        if !self.unsigned.is_empty() {
             len += 1;
         }
 
@@ -107,7 +107,7 @@ impl Serialize for CanonicalAliasEvent {
         state.serialize_field("state_key", &self.state_key)?;
         state.serialize_field("type", &self.event_type())?;
 
-        if self.unsigned.is_some() {
+        if !self.unsigned.is_empty() {
             state.serialize_field("unsigned", &self.unsigned)?;
         }
 
@@ -150,7 +150,8 @@ pub(crate) mod raw {
         pub state_key: String,
 
         /// Additional key-value pairs not signed by the homeserver.
-        pub unsigned: Option<Value>,
+        #[serde(default)]
+        pub unsigned: Map<String, Value>,
     }
 
     /// The payload of a `CanonicalAliasEvent`.
@@ -173,6 +174,7 @@ mod tests {
 
     use js_int::UInt;
     use ruma_identifiers::{EventId, RoomAliasId, UserId};
+    use serde_json::Map;
 
     use super::{CanonicalAliasEvent, CanonicalAliasEventContent};
     use crate::EventResult;
@@ -189,7 +191,7 @@ mod tests {
             room_id: None,
             sender: UserId::try_from("@carl:example.com").unwrap(),
             state_key: "".to_string(),
-            unsigned: None,
+            unsigned: Map::new(),
         };
 
         let actual = serde_json::to_string(&canonical_alias_event).unwrap();
diff --git a/src/room/encrypted.rs b/src/room/encrypted.rs
index e6eb7e9e..912e59a2 100644
--- a/src/room/encrypted.rs
+++ b/src/room/encrypted.rs
@@ -4,7 +4,7 @@ use std::collections::HashMap;
 use js_int::UInt;
 use ruma_identifiers::{DeviceId, EventId, RoomId, UserId};
 use serde::{ser::SerializeStruct, Deserialize, Deserializer, Serialize, Serializer};
-use serde_json::{from_value, Value};
+use serde_json::{from_value, Map, Value};
 
 use crate::{Algorithm, Event, EventType, FromRaw};
 
@@ -31,7 +31,7 @@ pub struct EncryptedEvent {
     pub sender: UserId,
 
     /// Additional key-value pairs not signed by the homeserver.
-    pub unsigned: Option<Value>,
+    pub unsigned: Map<String, Value>,
 }
 
 /// The payload for `EncryptedEvent`.
@@ -93,7 +93,7 @@ impl Serialize for EncryptedEvent {
             len += 1;
         }
 
-        if self.unsigned.is_some() {
+        if !self.unsigned.is_empty() {
             len += 1;
         }
 
@@ -110,7 +110,7 @@ impl Serialize for EncryptedEvent {
         state.serialize_field("sender", &self.sender)?;
         state.serialize_field("type", &self.event_type())?;
 
-        if self.unsigned.is_some() {
+        if !self.unsigned.is_empty() {
             state.serialize_field("unsigned", &self.unsigned)?;
         }
 
@@ -165,7 +165,8 @@ pub(crate) mod raw {
         pub sender: UserId,
 
         /// Additional key-value pairs not signed by the homeserver.
-        pub unsigned: Option<Value>,
+        #[serde(default)]
+        pub unsigned: Map<String, Value>,
     }
 
     /// The payload for `EncryptedEvent`.
diff --git a/src/room/member.rs b/src/room/member.rs
index 00bd5a21..e88f309e 100644
--- a/src/room/member.rs
+++ b/src/room/member.rs
@@ -225,7 +225,7 @@ mod tests {
 
     use js_int::UInt;
     use ruma_identifiers::{EventId, RoomId, UserId};
-    use serde_json::json;
+    use serde_json::{json, Map};
 
     use super::*;
     use crate::util::serde_json_eq_try_from_raw;
@@ -245,7 +245,7 @@ mod tests {
             room_id: Some(RoomId::try_from("!n8f893n9:example.com").unwrap()),
             sender: UserId::try_from("@carl:example.com").unwrap(),
             state_key: "example.com".to_string(),
-            unsigned: None,
+            unsigned: Map::new(),
             prev_content: None,
         };
         let json = json!({
@@ -277,7 +277,7 @@ mod tests {
             room_id: Some(RoomId::try_from("!n8f893n9:example.com").unwrap()),
             sender: UserId::try_from("@carl:example.com").unwrap(),
             state_key: "example.com".to_string(),
-            unsigned: None,
+            unsigned: Map::new(),
             prev_content: Some(MemberEventContent {
                 avatar_url: None,
                 displayname: None,
@@ -333,7 +333,7 @@ mod tests {
             room_id: Some(RoomId::try_from("!jEsUZKDJdhlrceRyVU:example.org").unwrap()),
             sender: UserId::try_from("@alice:example.org").unwrap(),
             state_key: "@alice:example.org".to_string(),
-            unsigned: None,
+            unsigned: Map::new(),
             prev_content: None,
         };
         let json = json!({
@@ -388,7 +388,7 @@ mod tests {
             room_id: Some(RoomId::try_from("!jEsUZKDJdhlrceRyVU:example.org").unwrap()),
             sender: UserId::try_from("@alice:example.org").unwrap(),
             state_key: "@alice:example.org".to_string(),
-            unsigned: None,
+            unsigned: Map::new(),
             prev_content: Some(MemberEventContent {
                 avatar_url: Some("mxc://example.org/SEsfnsuifSDFSSEF".to_owned()),
                 displayname: Some("Alice Margatroid".to_owned()),
diff --git a/src/room/message.rs b/src/room/message.rs
index 57fe736c..da81de4c 100644
--- a/src/room/message.rs
+++ b/src/room/message.rs
@@ -3,7 +3,7 @@
 use js_int::UInt;
 use ruma_identifiers::{EventId, RoomId, UserId};
 use serde::{ser::SerializeStruct, Deserialize, Deserializer, Serialize, Serializer};
-use serde_json::{from_value, Value};
+use serde_json::{from_value, Map, Value};
 
 use super::{EncryptedFile, ImageInfo, ThumbnailInfo};
 use crate::{Event, EventType, FromRaw};
@@ -30,7 +30,7 @@ pub struct MessageEvent {
     pub sender: UserId,
 
     /// Additional key-value pairs not signed by the homeserver.
-    pub unsigned: Option<Value>,
+    pub unsigned: Map<String, Value>,
 }
 
 /// The payload for `MessageEvent`.
@@ -119,7 +119,7 @@ impl Serialize for MessageEvent {
             len += 1;
         }
 
-        if self.unsigned.is_some() {
+        if !self.unsigned.is_empty() {
             len += 1;
         }
 
@@ -136,7 +136,7 @@ impl Serialize for MessageEvent {
         state.serialize_field("sender", &self.sender)?;
         state.serialize_field("type", &self.event_type())?;
 
-        if self.unsigned.is_some() {
+        if !self.unsigned.is_empty() {
             state.serialize_field("unsigned", &self.unsigned)?;
         }
 
@@ -193,7 +193,8 @@ pub(crate) mod raw {
         pub sender: UserId,
 
         /// Additional key-value pairs not signed by the homeserver.
-        pub unsigned: Option<Value>,
+        #[serde(default)]
+        pub unsigned: Map<String, Value>,
     }
 
     /// The payload for `MessageEvent`.
diff --git a/src/room/name.rs b/src/room/name.rs
index ee652523..42480455 100644
--- a/src/room/name.rs
+++ b/src/room/name.rs
@@ -3,7 +3,7 @@
 use js_int::UInt;
 use ruma_identifiers::{EventId, RoomId, UserId};
 use serde::{ser::SerializeStruct, Deserialize, Serialize, Serializer};
-use serde_json::Value;
+use serde_json::{Map, Value};
 
 use crate::{util::empty_string_as_none, Event as _, EventType, InvalidInput, TryFromRaw};
 
@@ -33,7 +33,7 @@ pub struct NameEvent {
     pub state_key: String,
 
     /// Additional key-value pairs not signed by the homeserver.
-    pub unsigned: Option<Value>,
+    pub unsigned: Map<String, Value>,
 }
 
 /// The payload for `NameEvent`.
@@ -92,7 +92,7 @@ impl Serialize for NameEvent {
             len += 1;
         }
 
-        if self.unsigned.is_some() {
+        if !self.unsigned.is_empty() {
             len += 1;
         }
 
@@ -114,7 +114,7 @@ impl Serialize for NameEvent {
         state.serialize_field("state_key", &self.state_key)?;
         state.serialize_field("type", &self.event_type())?;
 
-        if self.unsigned.is_some() {
+        if !self.unsigned.is_empty() {
             state.serialize_field("unsigned", &self.unsigned)?;
         }
 
@@ -175,7 +175,8 @@ pub(crate) mod raw {
         pub state_key: String,
 
         /// Additional key-value pairs not signed by the homeserver.
-        pub unsigned: Option<Value>,
+        #[serde(default)]
+        pub unsigned: Map<String, Value>,
     }
 
     /// The payload of a `NameEvent`.
@@ -196,7 +197,7 @@ mod tests {
 
     use js_int::UInt;
     use ruma_identifiers::{EventId, RoomId, UserId};
-    use serde_json::Value;
+    use serde_json::Map;
 
     use crate::EventResult;
 
@@ -214,7 +215,7 @@ mod tests {
             room_id: None,
             sender: UserId::try_from("@carl:example.com").unwrap(),
             state_key: "".to_string(),
-            unsigned: None,
+            unsigned: Map::new(),
         };
 
         let actual = serde_json::to_string(&name_event).unwrap();
@@ -237,7 +238,7 @@ mod tests {
             room_id: Some(RoomId::try_from("!n8f893n9:example.com").unwrap()),
             sender: UserId::try_from("@carl:example.com").unwrap(),
             state_key: "".to_string(),
-            unsigned: Some(serde_json::from_str::<Value>(r#"{"foo":"bar"}"#).unwrap()),
+            unsigned: serde_json::from_str(r#"{"foo":"bar"}"#).unwrap(),
         };
 
         let actual = serde_json::to_string(&name_event).unwrap();
diff --git a/src/room/pinned_events.rs b/src/room/pinned_events.rs
index 0812e133..8bb84d5e 100644
--- a/src/room/pinned_events.rs
+++ b/src/room/pinned_events.rs
@@ -21,7 +21,7 @@ mod tests {
 
     use js_int::UInt;
     use ruma_identifiers::{EventId, RoomId, UserId};
-    use serde_json::to_string;
+    use serde_json::{to_string, Map};
 
     use crate::{
         room::pinned_events::{PinnedEventsEvent, PinnedEventsEventContent},
@@ -43,7 +43,7 @@ mod tests {
             room_id: Some(RoomId::new("example.com").unwrap()),
             sender: UserId::new("example.com").unwrap(),
             state_key: "".to_string(),
-            unsigned: None,
+            unsigned: Map::new(),
         };
 
         let serialized_event = to_string(&event).unwrap();
diff --git a/src/room/power_levels.rs b/src/room/power_levels.rs
index 1497b386..aad4bd46 100644
--- a/src/room/power_levels.rs
+++ b/src/room/power_levels.rs
@@ -5,7 +5,7 @@ use std::collections::HashMap;
 use js_int::{Int, UInt};
 use ruma_identifiers::{EventId, RoomId, UserId};
 use serde::{ser::SerializeStruct, Deserialize, Serialize, Serializer};
-use serde_json::Value;
+use serde_json::{Map, Value};
 
 use crate::{Event as _, EventType, FromRaw};
 
@@ -29,7 +29,7 @@ pub struct PowerLevelsEvent {
     pub room_id: Option<RoomId>,
 
     /// Additional key-value pairs not signed by the homeserver.
-    pub unsigned: Option<Value>,
+    pub unsigned: Map<String, Value>,
 
     /// The unique identifier for the user who sent this event.
     pub sender: UserId,
@@ -139,7 +139,7 @@ impl Serialize for PowerLevelsEvent {
             len += 1;
         }
 
-        if self.unsigned.is_some() {
+        if !self.unsigned.is_empty() {
             len += 1;
         }
 
@@ -161,7 +161,7 @@ impl Serialize for PowerLevelsEvent {
         state.serialize_field("state_key", &self.state_key)?;
         state.serialize_field("type", &self.event_type())?;
 
-        if self.unsigned.is_some() {
+        if !self.unsigned.is_empty() {
             state.serialize_field("unsigned", &self.unsigned)?;
         }
 
@@ -198,7 +198,8 @@ pub(crate) mod raw {
         pub room_id: Option<RoomId>,
 
         /// Additional key-value pairs not signed by the homeserver.
-        pub unsigned: Option<Value>,
+        #[serde(default)]
+        pub unsigned: Map<String, Value>,
 
         /// The unique identifier for the user who sent this event.
         pub sender: UserId,
@@ -307,7 +308,7 @@ mod tests {
     use js_int::{Int, UInt};
     use maplit::hashmap;
     use ruma_identifiers::{EventId, RoomId, UserId};
-    use serde_json::Value;
+    use serde_json::Map;
 
     use super::{
         default_power_level, NotificationPowerLevels, PowerLevelsEvent, PowerLevelsEventContent,
@@ -335,7 +336,7 @@ mod tests {
             origin_server_ts: UInt::from(1u32),
             prev_content: None,
             room_id: None,
-            unsigned: None,
+            unsigned: Map::new(),
             sender: UserId::try_from("@carl:example.com").unwrap(),
             state_key: "".to_string(),
         };
@@ -390,7 +391,7 @@ mod tests {
                 },
             }),
             room_id: Some(RoomId::try_from("!n8f893n9:example.com").unwrap()),
-            unsigned: Some(serde_json::from_str::<Value>(r#"{"foo":"bar"}"#).unwrap()),
+            unsigned: serde_json::from_str(r#"{"foo":"bar"}"#).unwrap(),
             sender: user,
             state_key: "".to_string(),
         };
diff --git a/src/room/server_acl.rs b/src/room/server_acl.rs
index 5a1a054a..c0e63ed7 100644
--- a/src/room/server_acl.rs
+++ b/src/room/server_acl.rs
@@ -3,7 +3,7 @@
 use js_int::UInt;
 use ruma_identifiers::{EventId, RoomId, UserId};
 use serde::{ser::SerializeStruct, Deserialize, Serialize, Serializer};
-use serde_json::Value;
+use serde_json::{Map, Value};
 
 use crate::{util::default_true, Event as _, EventType, FromRaw};
 
@@ -33,7 +33,7 @@ pub struct ServerAclEvent {
     pub state_key: String,
 
     /// Additional key-value pairs not signed by the homeserver.
-    pub unsigned: Option<Value>,
+    pub unsigned: Map<String, Value>,
 }
 
 /// The payload for `ServerAclEvent`.
@@ -137,7 +137,8 @@ pub(crate) mod raw {
         pub room_id: Option<RoomId>,
 
         /// Additional key-value pairs not signed by the homeserver.
-        pub unsigned: Option<Value>,
+        #[serde(default)]
+        pub unsigned: Map<String, Value>,
 
         /// The unique identifier for the user who sent this event.
         pub sender: UserId,
diff --git a/tests/ruma_events_macros.rs b/tests/ruma_events_macros.rs
index 0cb96a9a..e1cf116c 100644
--- a/tests/ruma_events_macros.rs
+++ b/tests/ruma_events_macros.rs
@@ -4,7 +4,7 @@ use js_int::UInt;
 use ruma_events::util::serde_json_eq_try_from_raw;
 use ruma_events_macros::ruma_event;
 use ruma_identifiers::{EventId, RoomAliasId, RoomId, UserId};
-use serde_json::{json, Value};
+use serde_json::json;
 
 // See note about wrapping macro expansion in a module from `src/lib.rs`
 mod common_case {
@@ -34,7 +34,7 @@ mod common_case {
             room_id: None,
             sender: UserId::try_from("@carl:example.com").unwrap(),
             state_key: "example.com".to_string(),
-            unsigned: None,
+            unsigned: serde_json::Map::new(),
         };
         let json = json!({
             "content": {
@@ -63,7 +63,7 @@ mod common_case {
             room_id: Some(RoomId::try_from("!n8f893n9:example.com").unwrap()),
             sender: UserId::try_from("@carl:example.com").unwrap(),
             state_key: "example.com".to_string(),
-            unsigned: None,
+            unsigned: serde_json::Map::new(),
         };
         let json = json!({
             "content": {
@@ -96,7 +96,7 @@ mod common_case {
             room_id: Some(RoomId::try_from("!n8f893n9:example.com").unwrap()),
             sender: UserId::try_from("@carl:example.com").unwrap(),
             state_key: "example.com".to_string(),
-            unsigned: Some(serde_json::from_str::<Value>(r#"{"foo":"bar"}"#).unwrap()),
+            unsigned: serde_json::from_str(r#"{"foo":"bar"}"#).unwrap(),
         };
         let json = json!({
             "content": {
@@ -147,7 +147,7 @@ mod extra_fields {
             origin_server_ts: UInt::try_from(1).unwrap(),
             room_id: Some(RoomId::try_from("!n8f893n9:example.com").unwrap()),
             sender: UserId::try_from("@carl:example.com").unwrap(),
-            unsigned: Some(serde_json::from_str::<Value>(r#"{"foo":"bar"}"#).unwrap()),
+            unsigned: serde_json::from_str(r#"{"foo":"bar"}"#).unwrap(),
         };
         let json = json!({
             "content": {