diff --git a/src/ast.rs b/src/ast.rs
index 06f2bc4..4b7a2e7 100644
--- a/src/ast.rs
+++ b/src/ast.rs
@@ -206,7 +206,9 @@ impl AstDumper for ExprNode {
                 arguments,
             } => {
                 let callee = callee.dump();
-                if arguments.len() > 0 {
+                if arguments.is_empty() {
+                    format!("( call {} )", callee)
+                } else {
                     format!(
                         "( call {} {} )",
                         callee,
@@ -216,8 +218,6 @@ impl AstDumper for ExprNode {
                             .collect::<Vec<String>>()
                             .join(" ")
                     )
-                } else {
-                    format!("( call {} )", callee)
                 }
             }
         }
diff --git a/src/interpreter/value.rs b/src/interpreter/value.rs
index bc425e2..f337910 100644
--- a/src/interpreter/value.rs
+++ b/src/interpreter/value.rs
@@ -28,8 +28,8 @@ impl Value {
     /// Check whether a value is truthy or not.
     pub fn is_truthy(&self) -> bool {
         match self {
-            &Self::Nil => false,
-            &Self::Boolean(b) => b,
+            Self::Nil => false,
+            Self::Boolean(b) => *b,
             _ => true,
         }
     }