diff --git a/dmc-lib/src/ast/class.rs b/dmc-lib/src/ast/class.rs
index bd8e7fa..18095fa 100644
--- a/dmc-lib/src/ast/class.rs
+++ b/dmc-lib/src/ast/class.rs
@@ -1,6 +1,8 @@
 use crate::ast::field::Field;
 use crate::ast::function::Function;
+use crate::diagnostic::Diagnostic;
 use crate::source_range::SourceRange;
+use crate::symbol_table::SymbolTable;
 use std::rc::Rc;
 
 pub struct Class {
@@ -24,4 +26,19 @@ impl Class {
             functions,
         }
     }
+
+    pub fn gather_declared_names(
+        &mut self,
+        symbol_table: &mut SymbolTable,
+    ) -> Result<(), Vec<Diagnostic>> {
+        todo!()
+    }
+
+    pub fn check_name_usages(&mut self, symbol_table: &SymbolTable) -> Result<(), Vec<Diagnostic>> {
+        todo!()
+    }
+
+    pub fn type_check(&mut self, symbol_table: &SymbolTable) -> Result<(), Vec<Diagnostic>> {
+        todo!()
+    }
 }
diff --git a/dmc-lib/src/ast/compilation_unit.rs b/dmc-lib/src/ast/compilation_unit.rs
index f65db1f..2deea1e 100644
--- a/dmc-lib/src/ast/compilation_unit.rs
+++ b/dmc-lib/src/ast/compilation_unit.rs
@@ -1,19 +1,39 @@
-use crate::ast::module_level_declaration::ModuleLevelDeclaration;
+use crate::ast::class::Class;
+use crate::ast::extern_function::ExternFunction;
+use crate::ast::function::Function;
 use crate::diagnostic::Diagnostic;
 use crate::ir::ir_function::IrFunction;
 use crate::symbol_table::SymbolTable;
 
 pub struct CompilationUnit {
-    declarations: Vec<ModuleLevelDeclaration>,
+    functions: Vec<Function>,
+    extern_functions: Vec<ExternFunction>,
+    classes: Vec<Class>,
 }
 
 impl CompilationUnit {
-    pub fn new(declarations: Vec<ModuleLevelDeclaration>) -> Self {
-        Self { declarations }
+    pub fn new(
+        functions: Vec<Function>,
+        extern_functions: Vec<ExternFunction>,
+        classes: Vec<Class>,
+    ) -> Self {
+        Self {
+            functions,
+            extern_functions,
+            classes,
+        }
     }
 
-    pub fn declarations(&self) -> &[ModuleLevelDeclaration] {
-        &self.declarations
+    pub fn functions(&self) -> &[Function] {
+        &self.functions
+    }
+
+    pub fn extern_functions(&self) -> &[ExternFunction] {
+        &self.extern_functions
+    }
+
+    pub fn classes(&self) -> &[Class] {
+        &self.classes
     }
 
     pub fn gather_declared_names(
@@ -22,13 +42,27 @@ impl CompilationUnit {
     ) -> Result<(), Vec<Diagnostic>> {
         symbol_table.push_scope("compilation_unit_scope");
 
-        let diagnostics: Vec<Diagnostic> = self
-            .declarations
+        let mut diagnostics: Vec<Diagnostic> = vec![];
+        self.functions
             .iter_mut()
-            .map(|declaration| declaration.gather_declared_names(symbol_table))
+            .map(|f| f.gather_declared_names(symbol_table))
             .filter_map(Result::err)
             .flatten()
-            .collect();
+            .for_each(|diagnostic| diagnostics.push(diagnostic));
+
+        self.extern_functions
+            .iter_mut()
+            .map(|f| f.gather_declared_names(symbol_table))
+            .filter_map(Result::err)
+            .flatten()
+            .for_each(|diagnostic| diagnostics.push(diagnostic));
+
+        self.classes
+            .iter_mut()
+            .map(|c| c.gather_declared_names(symbol_table))
+            .filter_map(Result::err)
+            .flatten()
+            .for_each(|diagnostic| diagnostics.push(diagnostic));
 
         symbol_table.pop_scope();
 
@@ -40,13 +74,29 @@ impl CompilationUnit {
     }
 
     pub fn check_name_usages(&mut self, symbol_table: &SymbolTable) -> Result<(), Vec<Diagnostic>> {
-        let diagnostics: Vec<Diagnostic> = self
-            .declarations
+        let mut diagnostics: Vec<Diagnostic> = vec![];
+
+        self.functions
             .iter_mut()
-            .map(|declaration| declaration.check_name_usages(symbol_table))
+            .map(|f| f.check_name_usages(symbol_table))
             .filter_map(Result::err)
             .flatten()
-            .collect();
+            .for_each(|diagnostic| diagnostics.push(diagnostic));
+
+        self.extern_functions
+            .iter_mut()
+            .map(|f| f.check_name_usages(symbol_table))
+            .filter_map(Result::err)
+            .flatten()
+            .for_each(|diagnostic| diagnostics.push(diagnostic));
+
+        self.classes
+            .iter_mut()
+            .map(|c| c.check_name_usages(symbol_table))
+            .filter_map(Result::err)
+            .flatten()
+            .for_each(|diagnostic| diagnostics.push(diagnostic));
+
         if diagnostics.is_empty() {
             Ok(())
         } else {
@@ -55,13 +105,29 @@ impl CompilationUnit {
     }
 
     pub fn type_check(&mut self, symbol_table: &SymbolTable) -> Result<(), Vec<Diagnostic>> {
-        let diagnostics: Vec<Diagnostic> = self
-            .declarations
+        let mut diagnostics: Vec<Diagnostic> = vec![];
+
+        self.functions
             .iter_mut()
-            .map(|declaration| declaration.type_check(symbol_table))
+            .map(|f| f.type_check(symbol_table))
             .filter_map(Result::err)
             .flatten()
-            .collect();
+            .for_each(|diagnostic| diagnostics.push(diagnostic));
+
+        self.extern_functions
+            .iter_mut()
+            .map(|f| f.type_check(symbol_table))
+            .filter_map(Result::err)
+            .flatten()
+            .for_each(|diagnostic| diagnostics.push(diagnostic));
+
+        self.classes
+            .iter_mut()
+            .map(|c| c.type_check(symbol_table))
+            .filter_map(Result::err)
+            .flatten()
+            .for_each(|diagnostic| diagnostics.push(diagnostic));
+
         if diagnostics.is_empty() {
             Ok(())
         } else {
@@ -70,12 +136,9 @@ impl CompilationUnit {
     }
 
     pub fn to_ir(&self, symbol_table: &SymbolTable) -> Vec<IrFunction> {
-        let mut ir_functions = vec![];
-        for declaration in &self.declarations {
-            if let ModuleLevelDeclaration::Function(function) = declaration {
-                ir_functions.push(function.to_ir(symbol_table));
-            }
-        }
-        ir_functions
+        self.functions
+            .iter()
+            .map(|f| f.to_ir(symbol_table))
+            .collect()
     }
 }
diff --git a/dmc-lib/src/ast/mod.rs b/dmc-lib/src/ast/mod.rs
index b71053e..9f6e931 100644
--- a/dmc-lib/src/ast/mod.rs
+++ b/dmc-lib/src/ast/mod.rs
@@ -13,7 +13,6 @@ pub mod identifier;
 pub mod integer_literal;
 pub mod ir_builder;
 pub mod let_statement;
-pub mod module_level_declaration;
 pub mod negative_expression;
 pub mod parameter;
 pub mod statement;
diff --git a/dmc-lib/src/ast/module_level_declaration.rs b/dmc-lib/src/ast/module_level_declaration.rs
deleted file mode 100644
index c9a24a4..0000000
--- a/dmc-lib/src/ast/module_level_declaration.rs
+++ /dev/null
@@ -1,54 +0,0 @@
-use crate::ast::class::Class;
-use crate::ast::extern_function::ExternFunction;
-use crate::ast::function::Function;
-use crate::diagnostic::Diagnostic;
-use crate::symbol_table::SymbolTable;
-
-pub enum ModuleLevelDeclaration {
-    Function(Function),
-    ExternFunction(ExternFunction),
-    Class(Class),
-}
-
-impl ModuleLevelDeclaration {
-    pub fn gather_declared_names(
-        &mut self,
-        symbol_table: &mut SymbolTable,
-    ) -> Result<(), Vec<Diagnostic>> {
-        match self {
-            ModuleLevelDeclaration::Function(function) => {
-                function.gather_declared_names(symbol_table)
-            }
-            ModuleLevelDeclaration::ExternFunction(extern_function) => {
-                extern_function.gather_declared_names(symbol_table)
-            }
-            ModuleLevelDeclaration::Class(class) => {
-                todo!()
-            }
-        }
-    }
-
-    pub fn check_name_usages(&mut self, symbol_table: &SymbolTable) -> Result<(), Vec<Diagnostic>> {
-        match self {
-            ModuleLevelDeclaration::Function(function) => function.check_name_usages(symbol_table),
-            ModuleLevelDeclaration::ExternFunction(extern_function) => {
-                extern_function.check_name_usages(symbol_table)
-            }
-            ModuleLevelDeclaration::Class(class) => {
-                todo!()
-            }
-        }
-    }
-
-    pub fn type_check(&mut self, symbol_table: &SymbolTable) -> Result<(), Vec<Diagnostic>> {
-        match self {
-            ModuleLevelDeclaration::Function(function) => function.type_check(symbol_table),
-            ModuleLevelDeclaration::ExternFunction(extern_function) => {
-                extern_function.type_check(symbol_table)
-            }
-            ModuleLevelDeclaration::Class(class) => {
-                todo!()
-            }
-        }
-    }
-}
diff --git a/dmc-lib/src/ir/ir_block.rs b/dmc-lib/src/ir/ir_block.rs
index d9cfcb0..d177e3b 100644
--- a/dmc-lib/src/ir/ir_block.rs
+++ b/dmc-lib/src/ir/ir_block.rs
@@ -121,7 +121,6 @@ impl Display for IrBlock {
 
 #[cfg(test)]
 mod tests {
-    use crate::ast::module_level_declaration::ModuleLevelDeclaration;
     use crate::parser::parse_compilation_unit;
     use crate::symbol_table::SymbolTable;
 
@@ -139,22 +138,24 @@ mod tests {
         )
         .unwrap();
         let mut symbol_table = SymbolTable::new();
-        compilation_unit.gather_declared_names(&mut symbol_table);
-        compilation_unit.check_name_usages(&mut symbol_table);
-        compilation_unit.type_check(&mut symbol_table);
+        compilation_unit
+            .gather_declared_names(&mut symbol_table)
+            .expect("gather failed");
+        compilation_unit
+            .check_name_usages(&mut symbol_table)
+            .expect("name check failed");
+        compilation_unit
+            .type_check(&mut symbol_table)
+            .expect("type check failed");
 
         let main = compilation_unit
-            .declarations()
+            .functions()
             .iter()
-            .find(|d| matches!(d, ModuleLevelDeclaration::Function(_)))
+            .find(|f| f.declared_name() == "main")
             .unwrap();
 
-        if let ModuleLevelDeclaration::Function(main) = main {
-            let mut main_ir = main.to_ir(&symbol_table);
-            let (register_assignments, _) = main_ir.assign_registers(2);
-            assert_eq!(register_assignments.len(), 4);
-        } else {
-            unreachable!()
-        }
+        let mut main_ir = main.to_ir(&symbol_table);
+        let (register_assignments, _) = main_ir.assign_registers(2);
+        assert_eq!(register_assignments.len(), 4);
     }
 }
diff --git a/dmc-lib/src/parser.rs b/dmc-lib/src/parser.rs
index 654ef6e..8c1682e 100644
--- a/dmc-lib/src/parser.rs
+++ b/dmc-lib/src/parser.rs
@@ -11,7 +11,6 @@ use crate::ast::function::Function;
 use crate::ast::identifier::Identifier;
 use crate::ast::integer_literal::IntegerLiteral;
 use crate::ast::let_statement::LetStatement;
-use crate::ast::module_level_declaration::ModuleLevelDeclaration;
 use crate::ast::negative_expression::NegativeExpression;
 use crate::ast::parameter::Parameter;
 use crate::ast::statement::Statement;
@@ -189,16 +188,24 @@ impl<'a> Parser<'a> {
     }
 
     pub fn compilation_unit(&mut self) -> Result<CompilationUnit, Vec<Diagnostic>> {
-        let mut declarations = vec![];
+        let mut functions: Vec<Function> = vec![];
+        let mut extern_functions: Vec<ExternFunction> = vec![];
+        let mut classes: Vec<Class> = vec![];
+
         let mut diagnostics = vec![];
+
         self.advance(); // get started
+
         while self.current.is_some() {
             let current = self.get_current();
             match current.kind() {
                 TokenKind::Fn | TokenKind::Extern | TokenKind::Class => {
-                    let declaration_result = self.module_level_declaration();
-                    match declaration_result {
-                        Ok(declaration) => declarations.push(declaration),
+                    match self.module_level_declaration(
+                        &mut functions,
+                        &mut extern_functions,
+                        &mut classes,
+                    ) {
+                        Ok(_) => {}
                         Err(mut declaration_diagnostics) => {
                             diagnostics.append(&mut declaration_diagnostics)
                         }
@@ -219,19 +226,27 @@ impl<'a> Parser<'a> {
             }
         }
         if diagnostics.is_empty() {
-            Ok(CompilationUnit::new(declarations))
+            Ok(CompilationUnit::new(functions, extern_functions, classes))
         } else {
             Err(diagnostics)
         }
     }
 
-    fn module_level_declaration(&mut self) -> Result<ModuleLevelDeclaration, Vec<Diagnostic>> {
+    fn module_level_declaration(
+        &mut self,
+        functions: &mut Vec<Function>,
+        extern_functions: &mut Vec<ExternFunction>,
+        classes: &mut Vec<Class>,
+    ) -> Result<(), Vec<Diagnostic>> {
         let current = self.get_current();
         match current.kind() {
             TokenKind::Fn => {
                 let function_result = self.function();
                 match function_result {
-                    Ok(function) => Ok(ModuleLevelDeclaration::Function(function)),
+                    Ok(function) => {
+                        functions.push(function);
+                        Ok(())
+                    }
                     Err(function_diagnostics) => Err(function_diagnostics),
                 }
             }
@@ -239,13 +254,17 @@ impl<'a> Parser<'a> {
                 let extern_function_result = self.extern_function();
                 match extern_function_result {
                     Ok(extern_function) => {
-                        Ok(ModuleLevelDeclaration::ExternFunction(extern_function))
+                        extern_functions.push(extern_function);
+                        Ok(())
                     }
                     Err(extern_function_diagnostics) => Err(extern_function_diagnostics),
                 }
             }
             TokenKind::Class => match self.class() {
-                Ok(class) => Ok(ModuleLevelDeclaration::Class(class)),
+                Ok(class) => {
+                    classes.push(class);
+                    Ok(())
+                }
                 Err(class_diagnostics) => Err(class_diagnostics),
             },
             _ => unreachable!(),
@@ -865,29 +884,19 @@ mod concrete_tests {
         compilation_unit: &'a CompilationUnit,
         function_name: &str,
     ) -> &'a Function {
-        let declarations = compilation_unit.declarations();
-        for declaration in declarations {
-            match declaration {
-                ModuleLevelDeclaration::Function(function) => {
-                    if function.declared_name() == function_name {
-                        return function;
-                    }
-                }
-                _ => {}
-            }
-        }
-        panic!("Function {} not found", function_name)
+        compilation_unit
+            .functions()
+            .iter()
+            .find(|f| f.declared_name() == function_name)
+            .unwrap()
     }
 
     #[test]
     fn parses_extern_fn() {
         let compilation_unit = assert_compilation_unit("extern fn println() -> Void");
-        let declarations = compilation_unit.declarations();
-        assert_eq!(declarations.len(), 1);
-        let extern_function = match &declarations[0] {
-            ModuleLevelDeclaration::ExternFunction(extern_function) => extern_function,
-            _ => panic!(),
-        };
+        let extern_functions = compilation_unit.extern_functions();
+        assert_eq!(extern_functions.len(), 1);
+        let extern_function = &extern_functions[0];
         assert_eq!(extern_function.declared_name(), "println");
     }