diff --git a/src/machine.rs b/src/machine.rs
index 22a6b7a..2bb70f7 100644
--- a/src/machine.rs
+++ b/src/machine.rs
@@ -27,14 +27,14 @@ impl Machine {
 		}	
 	}
 
-	pub fn one_instruction(mut machine : Machine) -> Machine {
+	pub fn one_instruction(machine :&mut Machine) {
 	
 		let mut unsigned_reg1 : u64 = 0;
 		let mut unsigned_reg2 : u64 = 0;
 	
 		if machine.instructions.len() <= machine.pc as usize {
 			println!("ERROR : number max of instructions rushed");
-			return machine;
+			return ;
 		}
 
 		let inst : Instruction = decode(machine.instructions[machine.pc as usize]);
@@ -128,7 +128,6 @@ impl Machine {
 		}
 
 
-		machine
 	}
 }
 
diff --git a/src/main.rs b/src/main.rs
index 5f265bb..8a37ccd 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -6,5 +6,5 @@ use machine::Machine;
 fn main() {
     let mut m = Machine::_init_machine();
     m.instructions[0] = 0x37;
-    Machine::one_instruction(m);
+    Machine::one_instruction(&mut m);
 }