diff --git a/src/abstract_tree/function_call.rs b/src/abstract_tree/function_call.rs
index 802c57b..8d8cf83 100644
--- a/src/abstract_tree/function_call.rs
+++ b/src/abstract_tree/function_call.rs
@@ -12,6 +12,9 @@ pub struct FunctionCall {
     function_expression: FunctionExpression,
     arguments: Vec<Expression>,
     syntax_position: SourcePosition,
+
+    #[serde(skip)]
+    context: Context,
 }
 
 impl FunctionCall {
@@ -20,11 +23,13 @@ impl FunctionCall {
         function_expression: FunctionExpression,
         arguments: Vec<Expression>,
         syntax_position: SourcePosition,
+        context: Context,
     ) -> Self {
         Self {
             function_expression,
             arguments,
             syntax_position,
+            context,
         }
     }
 }
@@ -52,6 +57,7 @@ impl AbstractTree for FunctionCall {
             function_expression,
             arguments,
             syntax_position: node.range().into(),
+            context: Context::new(),
         })
     }
 
@@ -144,16 +150,20 @@ impl AbstractTree for FunctionCall {
             FunctionExpression::Value(value_node) => value_node.run(source, context)?,
             FunctionExpression::Index(index) => index.run(source, context)?,
         };
+        let function = value.as_function()?;
+        let parameter_expression_pairs = function
+            .parameters()
+            .unwrap()
+            .iter()
+            .zip(self.arguments.iter());
 
-        let mut arguments = Vec::with_capacity(self.arguments.len());
-
-        for expression in &self.arguments {
+        for (identifier, expression) in parameter_expression_pairs {
             let value = expression.run(source, context)?;
 
-            arguments.push(value);
+            self.context.set_value(identifier.inner().clone(), value)?;
         }
 
-        value.as_function()?.call(&arguments, source, context)
+        value.as_function()?.call(&[], source, context)
     }
 }
 
diff --git a/src/abstract_tree/function_node.rs b/src/abstract_tree/function_node.rs
index b468dc1..b498e63 100644
--- a/src/abstract_tree/function_node.rs
+++ b/src/abstract_tree/function_node.rs
@@ -14,9 +14,6 @@ pub struct FunctionNode {
     body: Block,
     r#type: Type,
     syntax_position: SourcePosition,
-
-    #[serde(skip)]
-    context: Context,
 }
 
 impl FunctionNode {
@@ -31,7 +28,6 @@ impl FunctionNode {
             body,
             r#type,
             syntax_position,
-            context: Context::new(),
         }
     }
 
@@ -61,21 +57,8 @@ impl FunctionNode {
         }
     }
 
-    pub fn call(
-        &self,
-        arguments: &[Value],
-        source: &str,
-        _context: &Context,
-    ) -> Result<Value, RuntimeError> {
-        let parameter_argument_pairs = self.parameters.iter().zip(arguments.iter());
-
-        for (identifier, value) in parameter_argument_pairs {
-            let key = identifier.inner().clone();
-
-            self.context.set_value(key, value.clone())?;
-        }
-
-        let return_value = self.body.run(source, &self.context)?;
+    pub fn call(&self, source: &str, context: &Context) -> Result<Value, RuntimeError> {
+        let return_value = self.body.run(source, context)?;
 
         Ok(return_value)
     }
@@ -108,15 +91,9 @@ impl AbstractTree for FunctionNode {
         let return_type_node = node.child(child_count - 2).unwrap();
         let return_type = TypeSpecification::from_syntax(return_type_node, source, context)?;
 
-        let function_context = Context::with_variables_from(context)?;
-
         let body_node = node.child(child_count - 1).unwrap();
         let body = Block::from_syntax(body_node, source, &context)?;
 
-        for (parameter, parameter_type) in parameters.iter().zip(parameter_types.iter()) {
-            function_context.set_type(parameter.inner().clone(), parameter_type.clone())?;
-        }
-
         let r#type = Type::function(parameter_types, return_type.take_inner());
         let syntax_position = node.range().into();
 
@@ -125,7 +102,6 @@ impl AbstractTree for FunctionNode {
             body,
             r#type,
             syntax_position,
-            context: function_context,
         })
     }
 
diff --git a/src/value/function.rs b/src/value/function.rs
index 050bf48..eb61600 100644
--- a/src/value/function.rs
+++ b/src/value/function.rs
@@ -4,7 +4,7 @@ use serde::{Deserialize, Serialize};
 
 use crate::{
     built_in_functions::Callable, error::RuntimeError, BuiltInFunction, Context, Format,
-    FunctionNode, Type, Value,
+    FunctionNode, Identifier, Type, Value,
 };
 
 #[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Serialize, Deserialize)]
@@ -24,9 +24,7 @@ impl Function {
             Function::BuiltIn(built_in_function) => {
                 built_in_function.call(arguments, source, outer_context)
             }
-            Function::ContextDefined(function_node) => {
-                function_node.call(arguments, source, outer_context)
-            }
+            Function::ContextDefined(function_node) => function_node.call(source, outer_context),
         }
     }
 
@@ -38,6 +36,14 @@ impl Function {
             }
         }
     }
+
+    pub fn parameters(&self) -> Option<&Vec<Identifier>> {
+        if let Function::ContextDefined(function) = self {
+            Some(function.parameters())
+        } else {
+            None
+        }
+    }
 }
 
 impl Format for Function {