diff --git a/schemars/src/flatten.rs b/schemars/src/flatten.rs
index 82f452c..506e719 100644
--- a/schemars/src/flatten.rs
+++ b/schemars/src/flatten.rs
@@ -35,12 +35,13 @@ macro_rules! impl_merge {
 }
 
 impl_merge!(SchemaObject {
-    merge: definitions extensions instance_type enum_values
+    merge: extensions instance_type enum_values
         metadata subschemas number string array object,
     or: format const_value reference,
 });
 
 impl_merge!(Metadata {
+    merge: definitions,
     or: schema id title description,
 });
 
diff --git a/schemars/src/gen.rs b/schemars/src/gen.rs
index f51d34d..725c3f4 100644
--- a/schemars/src/gen.rs
+++ b/schemars/src/gen.rs
@@ -129,7 +129,7 @@ impl SchemaGenerator {
         let metadata = schema.metadata.get_or_insert_with(Default::default);
         metadata.schema = Some("http://json-schema.org/draft-07/schema#".to_owned());
         metadata.title = Some(T::schema_name());
-        schema.definitions.extend(self.definitions().clone());
+        metadata.definitions.extend(self.definitions().clone());
         Ok(schema)
     }
 
@@ -138,7 +138,7 @@ impl SchemaGenerator {
         let metadata = schema.metadata.get_or_insert_with(Default::default);
         metadata.schema = Some("http://json-schema.org/draft-07/schema#".to_owned());
         metadata.title = Some(T::schema_name());
-        schema.definitions.extend(self.into_definitions());
+        metadata.definitions.extend(self.into_definitions());
         Ok(schema)
     }
 
diff --git a/schemars/src/schema.rs b/schemars/src/schema.rs
index eb19372..69bc8eb 100644
--- a/schemars/src/schema.rs
+++ b/schemars/src/schema.rs
@@ -48,8 +48,6 @@ pub struct SchemaObject {
     pub enum_values: Option<Vec<Value>>,
     #[serde(rename = "const", skip_serializing_if = "Option::is_none")]
     pub const_value: Option<Value>,
-    #[serde(alias = "$defs", skip_serializing_if = "Map::is_empty")]
-    pub definitions: Map<String, Schema>,
     #[serde(flatten, deserialize_with = "skip_if_default")]
     pub subschemas: Option<Box<SubschemaValidation>>,
     #[serde(flatten, deserialize_with = "skip_if_default")]
@@ -126,6 +124,8 @@ pub struct Metadata {
     pub title: Option<String>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub description: Option<String>,
+    #[serde(alias = "$defs", skip_serializing_if = "Map::is_empty")]
+    pub definitions: Map<String, Schema>,
 }
 
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Default, JsonSchema)]