1 files changed, 3 insertions, 3 deletions
diff --git a/third_party/rust/uniffi_bindgen/src/bindings/kotlin/templates/OptionalTemplate.kt b/third_party/rust/uniffi_bindgen/src/bindings/kotlin/templates/OptionalTemplate.kt
index 56cb5f87a5..98451e1451 100644
--- a/third_party/rust/uniffi_bindgen/src/bindings/kotlin/templates/OptionalTemplate.kt
+++ b/third_party/rust/uniffi_bindgen/src/bindings/kotlin/templates/OptionalTemplate.kt
@@ -8,11 +8,11 @@ public object {{ ffi_converter_name }}: FfiConverterRustBuffer<{{ inner_type_nam
         return {{ inner_type|read_fn }}(buf)
     }
 
-    override fun allocationSize(value: {{ inner_type_name }}?): Int {
+    override fun allocationSize(value: {{ inner_type_name }}?): ULong {
         if (value == null) {
-            return 1
+            return 1UL
         } else {
-            return 1 + {{ inner_type|allocation_size_fn }}(value)
+            return 1UL + {{ inner_type|allocation_size_fn }}(value)
         }
     }