diff --git a/rust/test/upb/accessors_test.rs b/rust/test/upb/accessors_test.rs
index ab909efae8..5e8cc717a2 100644
--- a/rust/test/upb/accessors_test.rs
+++ b/rust/test/upb/accessors_test.rs
@@ -40,3 +40,16 @@ fn test_optional_bool() {
     test_all_types.optional_bool_set(None);
     assert_eq!(test_all_types.optional_bool(), None);
 }
+
+#[test]
+fn test_optional_int64() {
+    let mut test_all_types: unittest_proto::TestAllTypes = unittest_proto::TestAllTypes::new();
+    test_all_types.optional_int64_set(Some(10));
+    assert_eq!(test_all_types.optional_int64(), Some(10));
+
+    test_all_types.optional_int64_set(Some(-10));
+    assert_eq!(test_all_types.optional_int64(), Some(-10));
+
+    test_all_types.optional_int64_set(None);
+    assert_eq!(test_all_types.optional_int64(), None);
+}
diff --git a/src/google/protobuf/compiler/rust/upb_kernel.cc b/src/google/protobuf/compiler/rust/upb_kernel.cc
index 8b0896123c..18fb0efdbd 100644
--- a/src/google/protobuf/compiler/rust/upb_kernel.cc
+++ b/src/google/protobuf/compiler/rust/upb_kernel.cc
@@ -65,22 +65,35 @@ bool IsSupported(const FieldDescriptor* field) {
   return field->is_optional() && !field->is_repeated();
 }
 
-void GenBoolAccessors(const std::string& upb_msg_prefix,
-                      const std::string& msg_name, const FieldDescriptor* field,
-                      google::protobuf::io::Printer& p) {
+absl::string_view RustTypeFromCppType(const FieldDescriptor::Type field_type) {
+  switch (field_type) {
+    case FieldDescriptor::Type::TYPE_BOOL:
+      return "bool";
+    case FieldDescriptor::Type::TYPE_INT64:
+      return "i64";
+    default: {
+      ABSL_LOG(FATAL) << "Unsupported field type: " << field_type;
+    }
+  }
+}
+
+void GenScalarAccessors(const std::string& upb_msg_prefix,
+                        const std::string& msg_name,
+                        const FieldDescriptor* field, google::protobuf::io::Printer& p) {
   if (!IsSupported(field)) {
     return;
   }
 
   p.Emit({{"Msg", msg_name},
           {"field_name", field->name()},
+          {"data_type", RustTypeFromCppType(field->type())},
           {"has_thunk", UpbThunkName(field, upb_msg_prefix, "_has_")},
           {"getter_thunk", UpbThunkName(field, upb_msg_prefix, "_")},
           {"setter_thunk", UpbThunkName(field, upb_msg_prefix, "_set_")},
           {"clear_thunk", UpbThunkName(field, upb_msg_prefix, "_clear_")}},
          R"rs(
           impl $Msg$ {
-            pub fn $field_name$(&self) -> Option<bool> {
+            pub fn $field_name$(&self) -> Option<$data_type$> {
               let field_present = unsafe { $has_thunk$(self.msg) };
               if !field_present {
                 return None;
@@ -89,7 +102,7 @@ void GenBoolAccessors(const std::string& upb_msg_prefix,
               Some(value)
             }
 
-            pub fn $field_name$_set(&mut self, value: Option<bool>) {
+            pub fn $field_name$_set(&mut self, value: Option<$data_type$>) {
               match value {
                 Some(value) => unsafe { $setter_thunk$(self.msg, value); },
                 None => unsafe { $clear_thunk$(self.msg); }
@@ -98,11 +111,11 @@ void GenBoolAccessors(const std::string& upb_msg_prefix,
           }
 
           extern "C" {
-            fn $getter_thunk$(msg: ::__std::ptr::NonNull<u8>) -> bool;
+            fn $getter_thunk$(msg: ::__std::ptr::NonNull<u8>) -> $data_type$;
             fn $has_thunk$(msg: ::__std::ptr::NonNull<u8>) -> bool;
             fn $setter_thunk$(
               msg: ::__std::ptr::NonNull<u8>,
-              value: bool
+              value: $data_type$
             );
             fn $clear_thunk$(msg: ::__std::ptr::NonNull<u8>);
           }
@@ -117,8 +130,9 @@ void GenFieldAccessors(const Descriptor* msg_descriptor,
     auto field = msg_descriptor->field(i);
 
     switch (field->type()) {
+      case FieldDescriptor::Type::TYPE_INT64:
       case FieldDescriptor::Type::TYPE_BOOL:
-        GenBoolAccessors(upb_msg_prefix, msg_descriptor->name(), field, p);
+        GenScalarAccessors(upb_msg_prefix, msg_descriptor->name(), field, p);
         break;
       default:
         // Not implemented type.