diff --git a/generators/x86_64.py b/generators/x86_64.py
index 894ea4d..8e47d02 100644
--- a/generators/x86_64.py
+++ b/generators/x86_64.py
@@ -29,6 +29,17 @@ class X86_64Generator(Generator):
 		)
 		self.pop(reg)
 
+	def change_variable(self, var_name: str, new_value):
+		var_pos = (self.stack_size - self.variables.get(var_name)['stack_loc'] - 1) * 8
+
+		if type(new_value) == NumberNode: # we're changing a variable to a number
+			self.lines.append(f"mov rax, {new_value.value}\n\t")
+			self.lines.append(f"mov QWORD [rsp + {var_pos}], rax\n\t")
+
+		elif type(new_value) == VarRefNode: # we're changing a variable to the value of another variable
+			self.get_variable(new_value.var_name, "rax")
+			self.lines.append(f"mov QWORD [rsp + {var_pos}], rax\n\t")
+
 	def generate_InstructionNode(self, node: InstructionNode):
 		if node.instruction == "end":
 			if len(node.arguments) == 0: # example: "end"
@@ -53,13 +64,19 @@ class X86_64Generator(Generator):
 				traceback(self.code, "TypeError", "set expects only 2 arguments.")
 			if not isinstance(node.arguments[0], VarPointerNode):
 				traceback(self.code, "TypeError", f"the first argument of set should be a variable pointer, not \"{type(node.arguments[0])}\"")
-			if type(node.arguments[1]) not in [NumberNode]:
+			if type(node.arguments[1]) not in [NumberNode, VarRefNode]:
 				traceback(self.code, "TypeError", f"variables can't be of type \"{type(node.arguments[1])}\"")
 
-			self.variables[node.arguments[0].var_name] = {"stack_loc": self.stack_size}
-			if type(node.arguments[1]) == NumberNode:
-				self.lines.append(f"mov rax, {node.arguments[1].value}\n\t")
-				self.push("rax")
+			variable_exists = self.variables.get(node.arguments[0].var_name, None) != None
+
+			if not variable_exists: # create a new variable
+				self.variables[node.arguments[0].var_name] = {"stack_loc": (self.stack_size), "type": type(node.arguments[1])}
+				if type(node.arguments[1]) == NumberNode:
+					self.lines.append(f"mov rax, {node.arguments[1].value}\n\t")
+					self.push("rax")
+			else: # modify the existing one
+				self.change_variable(node.arguments[0].var_name, node.arguments[1])
+
 				
 		else:
 			self.lines.append("; FUCK\n\t")
diff --git a/out b/out
index e5db3ec..71a7881 100644
Binary files a/out and b/out differ
diff --git a/out.asm b/out.asm
index 2b25660..843d179 100644
--- a/out.asm
+++ b/out.asm
@@ -1,15 +1,16 @@
 global _start
 
 _start:
-	; InstructionNode(instruction='set', parent=RootNode(statements=[..., InstructionNode(instruction='set', parent=..., arguments=[VariablePointer, Number]), InstructionNode(instruction='add', parent=..., arguments=[VariableReference, Number, VariablePointer]), InstructionNode(instruction='end', parent=..., arguments=[VariableReference])]), arguments=[VariablePointer, Number])
+	; InstructionNode(instruction='set', parent=RootNode(statements=[..., InstructionNode(instruction='set', parent=..., arguments=[VariablePointer, Number]), InstructionNode(instruction='set', parent=..., arguments=[VariablePointer, Number]), InstructionNode(instruction='end', parent=..., arguments=[VariableReference])]), arguments=[VariablePointer, Number])
 	mov rax, 66
 	push rax
-	; InstructionNode(instruction='set', parent=RootNode(statements=[InstructionNode(instruction='set', parent=..., arguments=[VariablePointer, Number]), ..., InstructionNode(instruction='add', parent=..., arguments=[VariableReference, Number, VariablePointer]), InstructionNode(instruction='end', parent=..., arguments=[VariableReference])]), arguments=[VariablePointer, Number])
+	; InstructionNode(instruction='set', parent=RootNode(statements=[InstructionNode(instruction='set', parent=..., arguments=[VariablePointer, Number]), ..., InstructionNode(instruction='set', parent=..., arguments=[VariablePointer, Number]), InstructionNode(instruction='end', parent=..., arguments=[VariableReference])]), arguments=[VariablePointer, Number])
 	mov rax, 69
 	push rax
-	; InstructionNode(instruction='add', parent=RootNode(statements=[InstructionNode(instruction='set', parent=..., arguments=[VariablePointer, Number]), InstructionNode(instruction='set', parent=..., arguments=[VariablePointer, Number]), ..., InstructionNode(instruction='end', parent=..., arguments=[VariableReference])]), arguments=[VariableReference, Number, VariablePointer])
-	; FUCK
-	; InstructionNode(instruction='end', parent=RootNode(statements=[InstructionNode(instruction='set', parent=..., arguments=[VariablePointer, Number]), InstructionNode(instruction='set', parent=..., arguments=[VariablePointer, Number]), InstructionNode(instruction='add', parent=..., arguments=[VariableReference, Number, VariablePointer]), ...]), arguments=[VariableReference])
+	; InstructionNode(instruction='set', parent=RootNode(statements=[InstructionNode(instruction='set', parent=..., arguments=[VariablePointer, Number]), InstructionNode(instruction='set', parent=..., arguments=[VariablePointer, Number]), ..., InstructionNode(instruction='end', parent=..., arguments=[VariableReference])]), arguments=[VariablePointer, Number])
+	mov rax, 123
+	mov QWORD [rsp + 8], rax
+	; InstructionNode(instruction='end', parent=RootNode(statements=[InstructionNode(instruction='set', parent=..., arguments=[VariablePointer, Number]), InstructionNode(instruction='set', parent=..., arguments=[VariablePointer, Number]), InstructionNode(instruction='set', parent=..., arguments=[VariablePointer, Number]), ...]), arguments=[VariableReference])
 	mov rax, 60
 	push QWORD [rsp + 8]
 	pop rdi
diff --git a/test2.grnd b/test2.grnd
index c6708e2..69e671d 100644
--- a/test2.grnd
+++ b/test2.grnd
@@ -1,4 +1,4 @@
 set &x 66
 set &y 69
-add $x 1 &x
+set &x 123
 end $x
\ No newline at end of file