diff --git a/core/iwasm/include/wasm_export.h b/core/iwasm/include/wasm_export.h
index 9a67aca422..a0eff541b2 100644
--- a/core/iwasm/include/wasm_export.h
+++ b/core/iwasm/include/wasm_export.h
@@ -1555,13 +1555,16 @@ wasm_runtime_get_context(wasm_module_inst_t inst, void *key);
  *
  * eg.
  *
- *   if (!wasm_runtime_begin_blocking_op) {
+ *   if (!wasm_runtime_begin_blocking_op(exec_env)) {
  *       return EINTR;
  *   }
  *   ret = possibly_blocking_op();
- *   wasm_runtime_end_blocking_op(env);
+ *   wasm_runtime_end_blocking_op(exec_env);
  *   return ret;
  *
+ * If threading support (WASM_ENABLE_THREAD_MGR) is not enabled,
+ * these functions are no-op.
+ *
  * If the underlying platform support (OS_ENABLE_WAKEUP_BLOCKING_OP) is
  * not available, these functions are no-op. In that case, the runtime
  * might not terminate a blocking thread in a timely manner.