diff --git a/rust_compiler/libs/compiler/src/v1.rs b/rust_compiler/libs/compiler/src/v1.rs
index 69cf3e9..61a26f0 100644
--- a/rust_compiler/libs/compiler/src/v1.rs
+++ b/rust_compiler/libs/compiler/src/v1.rs
@@ -2233,10 +2233,7 @@ impl<'a> Compiler<'a> {
             System::LoadSlot(dev_name, slot_index, logic_type) => {
                 let (dev_hash, hash_cleanup) =
                     self.compile_literal_or_variable(dev_name.node, scope)?;
-                let (slot_index, slot_cleanup) = self.compile_literal_or_variable(
-                    LiteralOrVariable::Literal(slot_index.node),
-                    scope,
-                )?;
+                let (slot_index, slot_cleanup) = self.compile_operand(*slot_index, scope)?;
                 let (logic_type, logic_cleanup) = self.compile_literal_or_variable(
                     LiteralOrVariable::Literal(logic_type.node),
                     scope,
@@ -2261,10 +2258,7 @@ impl<'a> Compiler<'a> {
             System::SetSlot(dev_name, slot_index, logic_type, var) => {
                 let (dev_name, name_cleanup) =
                     self.compile_literal_or_variable(dev_name.node, scope)?;
-                let (slot_index, index_cleanup) = self.compile_literal_or_variable(
-                    LiteralOrVariable::Literal(slot_index.node),
-                    scope,
-                )?;
+                let (slot_index, index_cleanup) = self.compile_operand(*slot_index, scope)?;
                 let (logic_type, type_cleanup) = self.compile_literal_or_variable(
                     LiteralOrVariable::Literal(logic_type.node),
                     scope,
diff --git a/rust_compiler/libs/parser/src/lib.rs b/rust_compiler/libs/parser/src/lib.rs
index 4cb4618..63e8ec2 100644
--- a/rust_compiler/libs/parser/src/lib.rs
+++ b/rust_compiler/libs/parser/src/lib.rs
@@ -1834,20 +1834,8 @@ impl<'a> Parser<'a> {
                 let mut args = args!(3);
                 let next = args.next();
                 let dev_name = literal_or_variable!(next);
-                let next = args.next();
-                let slot_index = get_arg!(Literal, literal_or_variable!(next));
-                if !matches!(
-                    slot_index,
-                    Spanned {
-                        node: Literal::Number(_),
-                        ..
-                    },
-                ) {
-                    return Err(Error::InvalidSyntax(
-                        slot_index.span,
-                        "Expected a number".to_string(),
-                    ));
-                }
+                let slot_index = args.next().ok_or(Error::UnexpectedEOF)?;
+
                 let next = args.next();
                 let slot_logic = get_arg!(Literal, literal_or_variable!(next));
                 if !matches!(
@@ -1864,27 +1852,17 @@ impl<'a> Parser<'a> {
                 }
 
                 Ok(SysCall::System(System::LoadSlot(
-                    dev_name, slot_index, slot_logic,
+                    dev_name,
+                    boxed!(slot_index),
+                    slot_logic,
                 )))
             }
             "setSlot" | "ss" => {
                 let mut args = args!(4);
                 let next = args.next();
                 let dev_name = literal_or_variable!(next);
-                let next = args.next();
-                let slot_index = get_arg!(Literal, literal_or_variable!(next));
-                if !matches!(
-                    slot_index,
-                    Spanned {
-                        node: Literal::Number(_),
-                        ..
-                    }
-                ) {
-                    return Err(Error::InvalidSyntax(
-                        slot_index.span,
-                        "Expected a number".into(),
-                    ));
-                }
+                let slot_index = args.next().ok_or(Error::UnexpectedEOF)?;
+
                 let next = args.next();
                 let slot_logic = get_arg!(Literal, literal_or_variable!(next));
                 if !matches!(
@@ -1904,9 +1882,9 @@ impl<'a> Parser<'a> {
 
                 Ok(SysCall::System(System::SetSlot(
                     dev_name,
-                    slot_index,
+                    boxed!(slot_index),
                     slot_logic,
-                    Box::new(expr),
+                    boxed!(expr),
                 )))
             }
             "loadReagent" | "lr" => {
diff --git a/rust_compiler/libs/parser/src/sys_call.rs b/rust_compiler/libs/parser/src/sys_call.rs
index 0251e91..67e03a9 100644
--- a/rust_compiler/libs/parser/src/sys_call.rs
+++ b/rust_compiler/libs/parser/src/sys_call.rs
@@ -223,7 +223,7 @@ documented! {
         /// `let isOccupied = ls(deviceHash, 2, "Occupied");`
         LoadSlot(
             Spanned<LiteralOrVariable<'a>>,
-            Spanned<Literal<'a>>,
+            Box<Spanned<Expression<'a>>>,
             Spanned<Literal<'a>>
         ),
         /// Stores a value of LogicType on a device by the index value
@@ -234,7 +234,7 @@ documented! {
         /// `ss(deviceHash, 0, "Open", true);`
         SetSlot(
             Spanned<LiteralOrVariable<'a>>,
-            Spanned<Literal<'a>>,
+            Box<Spanned<Expression<'a>>>,
             Spanned<Literal<'a>>,
             Box<Spanned<Expression<'a>>>
         ),