diff --git a/lykiadb-server/src/engine/interpreter.rs b/lykiadb-server/src/engine/interpreter.rs
index 4121623..0d7b696 100644
--- a/lykiadb-server/src/engine/interpreter.rs
+++ b/lykiadb-server/src/engine/interpreter.rs
@@ -15,7 +15,7 @@ use super::error::ExecutionError;
 
 use crate::plan::planner::Planner;
 use crate::util::{alloc_shared, Shared};
-use crate::value::callable::{Callable, CallableType, Function, Stateful};
+use crate::value::callable::{Callable, CallableKind, Function, Stateful};
 use crate::value::environment::{EnvId, Environment};
 use crate::value::types::{eval_binary, RV};
 
@@ -466,7 +466,7 @@ impl VisitorMut<RV, HaltReason> for Interpreter {
                     closure: self.env,
                 };
 
-                let callable = RV::Callable(Callable::new(Some(parameters.len()), CallableType::Any, fun.into()));
+                let callable = RV::Callable(Callable::new(Some(parameters.len()), CallableKind::Generic, fun.into()));
 
                 if name.is_some() {
                     // TODO(vck): Callable shouldn't be cloned here
diff --git a/lykiadb-server/src/engine/stdlib/mod.rs b/lykiadb-server/src/engine/stdlib/mod.rs
index f0e77bc..908b732 100644
--- a/lykiadb-server/src/engine/stdlib/mod.rs
+++ b/lykiadb-server/src/engine/stdlib/mod.rs
@@ -1,10 +1,8 @@
-use std::sync::Arc;
-
 use rustc_hash::FxHashMap;
 
 use crate::{
     util::{alloc_shared, Shared},
-    value::{callable::{Callable, CallableType, Function}, types::RV},
+    value::{callable::{Callable, CallableKind, Function}, types::RV},
 };
 
 use self::{
@@ -30,7 +28,7 @@ pub fn stdlib(out: Option<Shared<Output>>) -> FxHashMap<String, RV> {
 
     benchmark_namespace.insert(
         "fib".to_owned(),
-        RV::Callable(Callable::new(Some(1), CallableType::Any, Function::Lambda { function: nt_fib })),
+        RV::Callable(Callable::new(Some(1), CallableKind::Generic, Function::Lambda { function: nt_fib })),
     );
 
     json_namespace.insert(
@@ -38,7 +36,7 @@ pub fn stdlib(out: Option<Shared<Output>>) -> FxHashMap<String, RV> {
         RV::Callable(
             Callable::new(
                 Some(1),
-                CallableType::Any,
+                CallableKind::Generic,
                 Function::Lambda {
                     function: nt_json_encode,
                 }
@@ -50,7 +48,7 @@ pub fn stdlib(out: Option<Shared<Output>>) -> FxHashMap<String, RV> {
         "parse".to_owned(),
         RV::Callable(Callable::new(
             Some(1),
-            CallableType::Any,
+            CallableKind::Generic,
             Function::Lambda {
                 function: nt_json_decode,
             }),
@@ -61,7 +59,7 @@ pub fn stdlib(out: Option<Shared<Output>>) -> FxHashMap<String, RV> {
         "clock".to_owned(),
         RV::Callable(Callable::new(
             Some(0), 
-            CallableType::Any,
+            CallableKind::Generic,
             Function::Lambda { function: nt_clock }
         )),
     );
@@ -71,7 +69,7 @@ pub fn stdlib(out: Option<Shared<Output>>) -> FxHashMap<String, RV> {
 
         test_namespace.insert(
             "out".to_owned(),
-            RV::Callable(Callable::new(None, CallableType::Any, Function::Stateful(out.unwrap().clone()))),
+            RV::Callable(Callable::new(None, CallableKind::Generic, Function::Stateful(out.unwrap().clone()))),
         );
 
         std.insert(
@@ -88,7 +86,7 @@ pub fn stdlib(out: Option<Shared<Output>>) -> FxHashMap<String, RV> {
     std.insert("Time".to_owned(), RV::Object(alloc_shared(time_namespace)));
     std.insert(
         "print".to_owned(),
-        RV::Callable(Callable::new(None, CallableType::Any, Function::Lambda { function: nt_print })),
+        RV::Callable(Callable::new(None, CallableKind::Generic, Function::Lambda { function: nt_print })),
     );
 
     std
diff --git a/lykiadb-server/src/value/callable.rs b/lykiadb-server/src/value/callable.rs
index c58c7e2..65137f3 100644
--- a/lykiadb-server/src/value/callable.rs
+++ b/lykiadb-server/src/value/callable.rs
@@ -6,23 +6,23 @@ use super::environment::EnvId;
 use super::types::RV;
 
 #[derive(Debug, Clone)]
-pub enum CallableType {
-    Any,
+pub enum CallableKind {
+    Generic,
     Aggregator,
 }
 
 #[derive(Clone, Debug)]
 pub struct Callable {
     pub arity: Option<usize>,
-    pub call_type: CallableType,
+    pub kind: CallableKind,
     pub function: Arc<Function>,
 }
 
 impl Callable {
-    pub fn new(arity: Option<usize>, call_type: CallableType, function: Function) -> Self {
+    pub fn new(arity: Option<usize>, call_type: CallableKind, function: Function) -> Self {
         Callable {
             arity,
-            call_type,
+            kind: call_type,
             function: Arc::new(function),
         }
     }