diff --git a/schemars/src/_private/mod.rs b/schemars/src/_private/mod.rs
index 1e4f768c..3989f496 100644
--- a/schemars/src/_private/mod.rs
+++ b/schemars/src/_private/mod.rs
@@ -134,41 +134,30 @@ pub fn apply_internal_enum_variant_tag(
     }
 }
 
-pub fn insert_object_property<T: ?Sized + JsonSchema>(
+pub fn insert_object_property(
     schema: &mut Schema,
     key: &str,
-    may_be_omitted: bool,
-    required_attr: bool,
+    is_optional: bool,
     sub_schema: Schema,
 ) {
-    fn insert_object_property_impl(
-        schema: &mut Schema,
-        key: &str,
-        required: bool,
-        sub_schema: Schema,
-    ) {
-        let obj = schema.ensure_object();
-        if let Some(properties) = obj
-            .entry("properties")
-            .or_insert(Value::Object(Map::new()))
-            .as_object_mut()
-        {
-            properties.insert(key.to_owned(), sub_schema.into());
-        }
+    let obj = schema.ensure_object();
+    if let Some(properties) = obj
+        .entry("properties")
+        .or_insert(Value::Object(Map::new()))
+        .as_object_mut()
+    {
+        properties.insert(key.to_owned(), sub_schema.into());
+    }
 
-        if required {
-            if let Some(req) = obj
-                .entry("required")
-                .or_insert(Value::Array(Vec::new()))
-                .as_array_mut()
-            {
-                req.push(key.into());
-            }
+    if !is_optional {
+        if let Some(req) = obj
+            .entry("required")
+            .or_insert(Value::Array(Vec::new()))
+            .as_array_mut()
+        {
+            req.push(key.into());
         }
     }
-
-    let required = !may_be_omitted && (required_attr || !T::_schemars_private_is_option());
-    insert_object_property_impl(schema, key, required, sub_schema);
 }
 
 pub fn insert_metadata_property(schema: &mut Schema, key: &str, value: impl Into<Value>) {
diff --git a/schemars/tests/contract.rs b/schemars/tests/contract.rs
index 25bbb549..bd5160c0 100644
--- a/schemars/tests/contract.rs
+++ b/schemars/tests/contract.rs
@@ -16,6 +16,7 @@ struct MyStruct {
     skip_serializing_if: bool,
     #[schemars(rename(serialize = "ser_renamed", deserialize = "de_renamed"))]
     renamed: bool,
+    option: Option<bool>,
 }
 
 #[test]
diff --git a/schemars/tests/expected/contract_deserialize.json b/schemars/tests/expected/contract_deserialize.json
index b8f6680c..6b24d01d 100644
--- a/schemars/tests/expected/contract_deserialize.json
+++ b/schemars/tests/expected/contract_deserialize.json
@@ -16,6 +16,12 @@
     },
     "de_renamed": {
       "type": "boolean"
+    },
+    "option": {
+      "type": [
+        "boolean",
+        "null"
+      ]
     }
   },
   "required": [
diff --git a/schemars/tests/expected/contract_serialize.json b/schemars/tests/expected/contract_serialize.json
index 5d50b371..b82231fc 100644
--- a/schemars/tests/expected/contract_serialize.json
+++ b/schemars/tests/expected/contract_serialize.json
@@ -17,11 +17,18 @@
     },
     "ser_renamed": {
       "type": "boolean"
+    },
+    "OPTION": {
+      "type": [
+        "boolean",
+        "null"
+      ]
     }
   },
   "required": [
     "READ-ONLY",
     "DEFAULT",
-    "ser_renamed"
+    "ser_renamed",
+    "OPTION"
   ]
 }
\ No newline at end of file
diff --git a/schemars_derive/src/schema_exprs.rs b/schemars_derive/src/schema_exprs.rs
index 91d4f61d..0b30e2e6 100644
--- a/schemars_derive/src/schema_exprs.rs
+++ b/schemars_derive/src/schema_exprs.rs
@@ -509,16 +509,17 @@ fn expr_for_struct(
 
                 let has_default = set_container_default.is_some() || !field.serde_attrs.default().is_none();
                 let has_skip_serialize_if = field.serde_attrs.skip_serializing_if().is_some();
-                let may_be_omitted = if has_default == has_skip_serialize_if {
-                    has_default.into_token_stream()
+                let required_attr = field.attrs.validation.required;
+
+                let is_optional = if has_skip_serialize_if && has_default {
+                    quote!(true)
                 } else {
                     quote!(if #GENERATOR.contract().is_serialize() {
                         #has_skip_serialize_if
                     } else {
-                        #has_default
+                        #has_default || (!#required_attr && <#ty as schemars::JsonSchema>::_schemars_private_is_option())
                     })
                 };
-                let required_attr = field.attrs.validation.required;
 
                 let mut schema_expr = SchemaExpr::from(if field.attrs.validation.required {
                     quote_spanned! {ty.span()=>
@@ -538,11 +539,11 @@ fn expr_for_struct(
                     })
                 }
 
-                // embed `#type_def` outside of `#schema_expr`, because it's used as the type param
-                // (i.e. `#type_def` is the definition of `#ty`)
+                // embed `#type_def` outside of `#schema_expr`, because it's used as a type param
+                // in `#is_optional` (`#type_def` is the definition of `#ty`)
                 field.with_contract_check(quote!({
                     #type_def
-                    schemars::_private::insert_object_property::<#ty>(&mut #SCHEMA, #name, #may_be_omitted, #required_attr, #schema_expr);
+                    schemars::_private::insert_object_property(&mut #SCHEMA, #name, #is_optional, #schema_expr);
                 }))
             }
             })