diff --git a/script/src/lib.rs b/script/src/lib.rs
index 8b2d128039..7f73ca7ee6 100644
--- a/script/src/lib.rs
+++ b/script/src/lib.rs
@@ -8,6 +8,7 @@ mod verify;
 mod verify_env;
 
 pub use crate::error::{ScriptError, TransactionScriptError};
+pub use crate::syscalls::spawn::update_caller_machine;
 pub use crate::types::{
     CoreMachine, MachineContext, ResumableMachine, ScriptGroup, ScriptGroupType, ScriptVersion,
     TransactionSnapshot, TransactionState, VerifyResult, VmIsa, VmVersion,
diff --git a/script/src/syscalls/spawn.rs b/script/src/syscalls/spawn.rs
index 1f8e369d56..78f2c9715d 100644
--- a/script/src/syscalls/spawn.rs
+++ b/script/src/syscalls/spawn.rs
@@ -292,6 +292,7 @@ pub fn build_child_machine<
     Ok(machine_child)
 }
 
+/// Write the data generated by callee back to the caller memory space.
 pub fn update_caller_machine<Mac: SupportMachine>(
     caller: &mut Mac,
     callee_exit_code: i8,