diff --git a/src/generator.rs b/src/generator.rs
index b5eb016..362e464 100644
--- a/src/generator.rs
+++ b/src/generator.rs
@@ -231,9 +231,9 @@ impl CodeGen for Block {
                                 })
                             },
                             Some(multiple_param) => {
-                                let num_multiple = multiple_param.multiple;
+                                let num_multiple = multiple_param.multiple as usize;
                                 let elements = (0..num_multiple).map(|i| {
-                                    let offset = multiple_param.offset * i;
+                                    let offset = (multiple_param.offset as usize) * i;
                                     quote! {
                                         #snake_case_name::#child_upper_camel_name::new(unsafe { self.mem_ptr.add(#offset) } )
                                     }