diff --git a/lib/pinc_bytecode/instruction.ml b/lib/pinc_bytecode/instruction.ml
index f53c2b3..46bbabc 100644
--- a/lib/pinc_bytecode/instruction.ml
+++ b/lib/pinc_bytecode/instruction.ml
@@ -90,19 +90,19 @@ let byte = function
 ;;
 
 let operands_length = function
-  | I_Constant op
-  | I_Jump op
-  | I_Jump_If_False op
-  | I_Set_Global op
-  | I_Get_Global op
-  | I_Array op
-  | I_Record op
-  | I_Set_Local op
-  | I_Get_Local op
-  | I_Get_Builtin op
-  | I_Get_Free op
-  | I_Call op -> Int32.byte_width op
-  | I_Closure (op1, op2) -> Int32.byte_width op1 + Int32.byte_width op2
+  | I_Constant _
+  | I_Jump _
+  | I_Jump_If_False _
+  | I_Set_Global _
+  | I_Get_Global _
+  | I_Array _
+  | I_Record _
+  | I_Set_Local _
+  | I_Get_Local _
+  | I_Get_Builtin _
+  | I_Get_Free _
+  | I_Call _ -> Int32.byte_width
+  | I_Closure (_, _) -> Int32.byte_width * 2
   | I_Pop
   | I_Add
   | I_Sub
diff --git a/lib/pinc_core/StdlibExtension.ml b/lib/pinc_core/StdlibExtension.ml
index 8433d1e..8dea7a1 100644
--- a/lib/pinc_core/StdlibExtension.ml
+++ b/lib/pinc_core/StdlibExtension.ml
@@ -199,16 +199,16 @@ end
 module Int32 = struct
   include Int32
 
-  let byte_width (_ : Int32.t) = 4
+  let byte_width = 4
 
   let write_bytes bytes offset t =
     Bytes.set_int32_be bytes offset t;
-    offset + byte_width t
+    offset + byte_width
   ;;
 
   let read_bytes bytes offset =
     let result = Bytes.get_int32_be bytes offset in
-    (offset + byte_width result, result)
+    (offset + byte_width, result)
   ;;
 
   let pp fmt t = Format.fprintf fmt "0x%08lX (%08li)" t t