diff --git a/dust-lang/src/parse.rs b/dust-lang/src/parse.rs
index bb1844e..2437146 100644
--- a/dust-lang/src/parse.rs
+++ b/dust-lang/src/parse.rs
@@ -256,26 +256,8 @@ impl<'src> Parser<'src> {
             (Token::IsEven, left_span) => {
                 self.next_token()?;
 
-                let mut value_parameters = None;
-
                 if let (Token::LeftParenthesis, _) = self.current {
                     self.next_token()?;
-
-                    value_parameters = Some(vec![self.parse_node(0)?]);
-
-                    loop {
-                        self.next_token()?;
-
-                        if let (Token::RightParenthesis, _) = self.current {
-                            break;
-                        }
-
-                        if let (Token::Comma, _) = self.current {
-                            self.next_token()?;
-                        }
-
-                        value_parameters.as_mut().unwrap().push(self.parse_node(0)?);
-                    }
                 } else {
                     return Err(ParseError::ExpectedOpeningParenthesis {
                         actual: self.current.0.clone(),
@@ -296,7 +278,7 @@ impl<'src> Parser<'src> {
                     Statement::BuiltInFunctionCall {
                         function: BuiltInFunction::IsEven,
                         type_arguments: None,
-                        value_arguments: value_parameters,
+                        value_arguments: None,
                     },
                     left_span,
                 ))
diff --git a/dust-lang/src/vm.rs b/dust-lang/src/vm.rs
index 8bf82e2..5d3c76f 100644
--- a/dust-lang/src/vm.rs
+++ b/dust-lang/src/vm.rs
@@ -213,13 +213,11 @@ impl<P: Copy> Vm<P> {
                     },
                 ) = (left_value, right.statement)
                 {
-                    if let Some(mut nodes) = value_argument_nodes.take() {
-                        nodes.insert(0, Node::new(Statement::Constant(value), right_span));
-                    }
+                    let mut value_arguments = Vec::new();
 
-                    let value_arguments = if let Some(value_nodes) = value_argument_nodes {
-                        let mut value_arguments = Vec::new();
+                    value_arguments.push(value);
 
+                    if let Some(value_nodes) = value_argument_nodes {
                         for node in value_nodes {
                             let position = node.position;
                             let value = if let Some(value) = self.run_node(node, variables)? {
@@ -230,13 +228,9 @@ impl<P: Copy> Vm<P> {
 
                             value_arguments.push(value);
                         }
+                    }
 
-                        Some(value_arguments)
-                    } else {
-                        None
-                    };
-
-                    let function_call_return = function.call(None, value_arguments)?;
+                    let function_call_return = function.call(None, Some(value_arguments))?;
 
                     return Ok(Some(function_call_return));
                 }