diff --git a/src/name_analysis/fqn_context.rs b/src/name_analysis/fqn_context.rs
index 7589f3a..fd3ef36 100644
--- a/src/name_analysis/fqn_context.rs
+++ b/src/name_analysis/fqn_context.rs
@@ -1,4 +1,4 @@
-pub(super) struct FqnContext {
+pub struct FqnContext {
     stack: Vec<String>,
 }
 
diff --git a/src/name_analysis/gather.rs b/src/name_analysis/gather.rs
index 082035b..3a2d75b 100644
--- a/src/name_analysis/gather.rs
+++ b/src/name_analysis/gather.rs
@@ -1,16 +1,20 @@
 use crate::ast::ast_node::{AstNode, AstNodeRef};
 use crate::ast::node::{
-    CompilationUnit, Function, FunctionBlockBody, FunctionBody, Identifier, Statement,
-    UseStatement, UseStatementSuffix, VariableDeclaration,
+    Class, CompilationUnit, Function, FunctionBlockBody, FunctionBody, Identifier, Interface,
+    Module, Namespace, Statement, UseStatement, UseStatementSuffix, VariableDeclaration,
 };
 use crate::diagnostic::DmDiagnostic;
+use crate::name_analysis::fqn_context::FqnContext;
 use crate::name_analysis::symbol::function_symbol::FunctionSymbol;
+use crate::name_analysis::symbol::module_symbol::ModuleSymbol;
 use crate::name_analysis::symbol::source_definition::SourceDefinition;
+use crate::name_analysis::symbol::type_symbol::{
+    ConcreteTypeSymbol, ConcreteTypeSymbolKind, TypeSymbol,
+};
 use crate::name_analysis::symbol::use_symbol::{ConcreteUseSymbol, StarUseSymbol};
 use crate::name_analysis::symbol::variable_symbol::VariableSymbol;
 use crate::name_analysis::symbol_table::{SymbolInsertError, SymbolTable};
 use codespan_reporting::diagnostic::{Diagnostic, Label};
-use std::collections::HashMap;
 use std::range::Range;
 
 fn handle_insert_error(
@@ -45,165 +49,28 @@ fn handle_insert_error(
     }
 }
 
-fn gather_identifier(
-    identifier: &Identifier,
-    symbol_table: &SymbolTable,
-    identifier_scope_ids: &mut HashMap<Identifier, usize>,
-) {
-    identifier_scope_ids.insert(identifier.clone(), symbol_table.current_scope_id());
-}
-
-fn gather_concrete_use_symbol(
-    base_fqn: &str,
-    identifier: &Identifier,
-    symbol_table: &mut SymbolTable,
-    diagnostics: &mut Vec<DmDiagnostic>,
-) {
-    let symbol = ConcreteUseSymbol::new(
-        base_fqn,
-        identifier.name(),
-        Some(SourceDefinition::from_identifier(identifier)),
-    );
-    if let Err(insert_error) = symbol_table.insert_concrete_use_symbol(symbol) {
-        handle_insert_error(
-            insert_error,
-            &base_fqn,
-            identifier.file_id(),
-            identifier.range(),
-            "Use Statement",
-            diagnostics,
-        );
-    }
-}
-
-fn gather_use_statement(
-    use_statement: &UseStatement,
-    symbol_table: &mut SymbolTable,
-    diagnostics: &mut Vec<DmDiagnostic>,
-) {
-    let base_fqn = use_statement
-        .prefixes()
-        .map(|prefix| prefix.identifier().name())
-        .collect::<Vec<_>>()
-        .join("::");
-
-    match use_statement.suffix() {
-        UseStatementSuffix::Identifier(identifier) => {
-            gather_concrete_use_symbol(&base_fqn, identifier, symbol_table, diagnostics);
-        }
-        UseStatementSuffix::Star => {
-            let symbol = StarUseSymbol::new(
-                &base_fqn,
-                Some(SourceDefinition::from_use_statement(use_statement)),
-            );
-            let insert_result = symbol_table.insert_star_use_symbol(symbol);
-            if let Err(error) = insert_result {
-                handle_insert_error(
-                    error,
-                    &base_fqn,
-                    use_statement.file_id(),
-                    use_statement.range(),
-                    "Use Statement",
-                    diagnostics,
-                );
-            }
-        }
-        UseStatementSuffix::UseList(use_list) => {
-            for identifier in use_list.identifiers() {
-                gather_concrete_use_symbol(&base_fqn, identifier, symbol_table, diagnostics);
-            }
-        }
-    }
-}
-
-fn gather_function(
-    function: &Function,
-    symbol_table: &mut SymbolTable,
-    diagnostics: &mut Vec<DmDiagnostic>,
-) {
-    let function_symbol = FunctionSymbol::without_parameters_or_return_type(
-        "",
-        function.identifier().name(),
-        function.is_public(),
-        false,
-        Some(SourceDefinition::from_identifier(function.identifier())),
-    );
-    if let Err(insert_error) = symbol_table.insert_function_symbol(function_symbol) {
-        handle_insert_error(
-            insert_error,
-            function.identifier().name(),
-            function.identifier().file_id(),
-            function.identifier().range(),
-            "Function",
-            diagnostics,
-        );
-    }
-    gather_node(
-        AstNodeRef::FunctionBody(function.function_body()),
-        symbol_table,
-        diagnostics,
-    );
-}
-
-fn gather_function_block_body(
-    function_block_body: &FunctionBlockBody,
-    symbol_table: &mut SymbolTable,
-    diagnostics: &mut Vec<DmDiagnostic>,
-) {
-    symbol_table.push_scope("FunctionBlockBody");
-    gather_node_children(function_block_body, symbol_table, diagnostics);
-    symbol_table.pop_scope();
-}
-
-fn gather_variable_declaration(
-    variable_declaration: &VariableDeclaration,
-    symbol_table: &mut SymbolTable,
-    diagnostics: &mut Vec<DmDiagnostic>,
-) {
-    let variable_symbol = VariableSymbol::new(
-        variable_declaration.identifier().name(),
-        variable_declaration.is_mut(),
-        Some(SourceDefinition::from_identifier(
-            variable_declaration.identifier(),
-        )),
-    );
-    if let Err(insert_error) = symbol_table.insert_variable_symbol(variable_symbol) {
-        handle_insert_error(
-            insert_error,
-            variable_declaration.identifier().name(),
-            variable_declaration.identifier().file_id(),
-            variable_declaration.identifier().range(),
-            "Variable",
-            diagnostics,
-        );
-    }
-    if let Some(expression) = variable_declaration.expression() {
-        gather_node(
-            AstNodeRef::Expression(expression),
-            symbol_table,
-            diagnostics,
-        );
-    }
-}
-
 fn gather_node_children(
     node: &impl AstNode,
     symbol_table: &mut SymbolTable,
+    fqn_context: &mut FqnContext,
     diagnostics: &mut Vec<DmDiagnostic>,
 ) {
     for child in node.children() {
-        gather_node(child, symbol_table, diagnostics);
+        gather_node(child, symbol_table, fqn_context, diagnostics);
     }
 }
 
 fn gather_node(
     node: AstNodeRef,
     symbol_table: &mut SymbolTable,
+    fqn_context: &mut FqnContext,
     diagnostics: &mut Vec<DmDiagnostic>,
 ) {
     match node {
         AstNodeRef::Operator(_) => {}
-        AstNodeRef::Identifier(_) => {}
+        AstNodeRef::Identifier(_) => {
+            unreachable!()
+        }
         AstNodeRef::FullyQualifiedName(_) => {}
         AstNodeRef::TypeUseList(_) => {}
         AstNodeRef::IdentifierList(_) => {}
@@ -222,26 +89,58 @@ fn gather_node(
         AstNodeRef::Parameter(_) => {}
         AstNodeRef::ReturnType(_) => {}
         AstNodeRef::CompilationUnit(compilation_unit) => {
-            gather_node_children(compilation_unit, symbol_table, diagnostics);
+            gather_node_children(compilation_unit, symbol_table, fqn_context, diagnostics);
+        }
+        AstNodeRef::Namespace(namespace) => {
+            gather_namespace(namespace, fqn_context);
         }
-        AstNodeRef::ParentMod(_) => {}
         AstNodeRef::UseStatement(use_statement) => {
             gather_use_statement(use_statement, symbol_table, diagnostics);
         }
-        AstNodeRef::UseStatementPrefix(_) => {}
-        AstNodeRef::UseStatementSuffix(_) => {}
-        AstNodeRef::UseList(_) => {}
-        AstNodeRef::ModuleLevelDeclaration(module_level_declaration) => {
-            gather_node_children(module_level_declaration, symbol_table, diagnostics);
+        AstNodeRef::UseStatementPrefix(_) => {
+            unreachable!()
+        }
+        AstNodeRef::UseStatementSuffix(_) => {
+            unreachable!()
+        }
+        AstNodeRef::UseList(_) => {
+            unreachable!()
+        }
+        AstNodeRef::ModuleLevelDeclaration(module_level_declaration) => {
+            gather_node_children(
+                module_level_declaration,
+                symbol_table,
+                fqn_context,
+                diagnostics,
+            );
+        }
+        AstNodeRef::InterfaceLevelDeclaration(interface_level_declaration) => {
+            gather_node_children(
+                interface_level_declaration,
+                symbol_table,
+                fqn_context,
+                diagnostics,
+            );
+        }
+        AstNodeRef::ClassLevelDeclaration(class_level_declaration) => {
+            gather_node_children(
+                class_level_declaration,
+                symbol_table,
+                fqn_context,
+                diagnostics,
+            );
+        }
+        AstNodeRef::Module(module) => {
+            gather_module(module, symbol_table, fqn_context, diagnostics);
+        }
+        AstNodeRef::Interface(interface) => {
+            gather_interface(interface, symbol_table, fqn_context, diagnostics);
+        }
+        AstNodeRef::Class(class) => {
+            gather_class(class, symbol_table, fqn_context, diagnostics);
         }
-        AstNodeRef::InterfaceLevelDeclaration(_) => {}
-        AstNodeRef::ClassLevelDeclaration(_) => {}
-        AstNodeRef::Module(_) => {}
-        AstNodeRef::CompanionModule(_) => {}
-        AstNodeRef::Interface(_) => {}
-        AstNodeRef::Class(_) => {}
         AstNodeRef::Function(function) => {
-            gather_function(function, symbol_table, diagnostics);
+            gather_function(function, symbol_table, fqn_context, diagnostics);
         }
         AstNodeRef::OperatorFunction(_) => {}
         AstNodeRef::PlatformFunction(_) => {}
@@ -251,25 +150,45 @@ fn gather_node(
         AstNodeRef::InterfaceDefaultOperatorFunction(_) => {}
         AstNodeRef::FunctionBody(function_body) => match function_body {
             FunctionBody::FunctionAliasBody(alias_body) => {
-                gather_node(alias_body.as_node_ref(), symbol_table, diagnostics);
+                gather_node(
+                    alias_body.as_node_ref(),
+                    symbol_table,
+                    fqn_context,
+                    diagnostics,
+                );
             }
             FunctionBody::FunctionEqualsBody(equals_body) => {
-                gather_node(equals_body.as_node_ref(), symbol_table, diagnostics);
+                gather_node(
+                    equals_body.as_node_ref(),
+                    symbol_table,
+                    fqn_context,
+                    diagnostics,
+                );
             }
             FunctionBody::FunctionBlockBody(block_body) => {
-                gather_node(block_body.as_node_ref(), symbol_table, diagnostics);
+                gather_node(
+                    block_body.as_node_ref(),
+                    symbol_table,
+                    fqn_context,
+                    diagnostics,
+                );
             }
         },
         AstNodeRef::FunctionEqualsBody(_) => {}
         AstNodeRef::FunctionAliasBody(_) => {}
         AstNodeRef::FunctionBlockBody(block_body) => {
-            gather_function_block_body(block_body, symbol_table, diagnostics);
+            gather_function_block_body(block_body, symbol_table, fqn_context, diagnostics);
         }
         AstNodeRef::ClassConstructor(_) => {}
         AstNodeRef::Member(_) => {}
         AstNodeRef::Statement(statement) => match statement {
             Statement::VariableDeclaration(variable_declaration) => {
-                gather_variable_declaration(variable_declaration, symbol_table, diagnostics);
+                gather_node(
+                    variable_declaration.as_node_ref(),
+                    symbol_table,
+                    fqn_context,
+                    diagnostics,
+                );
             }
             Statement::AssignmentStatement(_) => {}
             Statement::ExpressionStatement(_) => {}
@@ -332,10 +251,282 @@ pub fn gather_compilation_unit(
     compilation_unit: &mut CompilationUnit,
     file_name: &str,
     symbol_table: &mut SymbolTable,
-    identifier_scope_ids: &mut HashMap<Identifier, usize>,
     diagnostics: &mut Vec<DmDiagnostic>,
 ) {
+    let mut fqn_context = FqnContext::new();
     symbol_table.push_scope(&format!("FileScope {}", file_name));
-    gather_node(compilation_unit.as_node_ref(), symbol_table, diagnostics);
+    gather_node(
+        compilation_unit.as_node_ref(),
+        symbol_table,
+        &mut fqn_context,
+        diagnostics,
+    );
     symbol_table.pop_scope();
 }
+
+fn gather_namespace(namespace: &Namespace, fqn_context: &mut FqnContext) {
+    for identifier in namespace.fqn().identifiers() {
+        fqn_context.push(identifier.name());
+    }
+}
+
+fn gather_use_statement(
+    use_statement: &UseStatement,
+    symbol_table: &mut SymbolTable,
+    diagnostics: &mut Vec<DmDiagnostic>,
+) {
+    let base_fqn = use_statement
+        .prefixes()
+        .map(|prefix| prefix.identifier().name())
+        .collect::<Vec<_>>()
+        .join("::");
+
+    match use_statement.suffix() {
+        UseStatementSuffix::Identifier(identifier) => {
+            gather_concrete_use_symbol(&base_fqn, identifier, symbol_table, diagnostics);
+        }
+        UseStatementSuffix::Star => {
+            let symbol = StarUseSymbol::new(
+                &base_fqn,
+                Some(SourceDefinition::from_use_statement(use_statement)),
+            );
+            let insert_result = symbol_table.insert_star_use_symbol(symbol);
+            if let Err(error) = insert_result {
+                handle_insert_error(
+                    error,
+                    &base_fqn,
+                    use_statement.file_id(),
+                    use_statement.range(),
+                    "Use Statement",
+                    diagnostics,
+                );
+            }
+        }
+        UseStatementSuffix::UseList(use_list) => {
+            for identifier in use_list.identifiers() {
+                gather_concrete_use_symbol(&base_fqn, identifier, symbol_table, diagnostics);
+            }
+        }
+    }
+}
+
+fn gather_concrete_use_symbol(
+    base_fqn: &str,
+    identifier: &Identifier,
+    symbol_table: &mut SymbolTable,
+    diagnostics: &mut Vec<DmDiagnostic>,
+) {
+    let symbol = ConcreteUseSymbol::new(
+        base_fqn,
+        identifier.name(),
+        Some(SourceDefinition::from_identifier(identifier)),
+    );
+    if let Err(insert_error) = symbol_table.insert_concrete_use_symbol(symbol) {
+        handle_insert_error(
+            insert_error,
+            &base_fqn,
+            identifier.file_id(),
+            identifier.range(),
+            "Use Statement",
+            diagnostics,
+        );
+    }
+}
+
+fn gather_module(
+    module: &Module,
+    symbol_table: &mut SymbolTable,
+    fqn_context: &mut FqnContext,
+    diagnostics: &mut Vec<DmDiagnostic>,
+) {
+    let module_symbol = ModuleSymbol::new(
+        &fqn_context.resolve(module.identifier().name()),
+        module.identifier().name(),
+        module.is_public(),
+        Some(SourceDefinition::from_identifier(module.identifier())),
+    );
+    if let Err(symbol_insert_error) = symbol_table.insert_module_symbol(module_symbol) {
+        handle_insert_error(
+            symbol_insert_error,
+            module.identifier().name(),
+            module.identifier().file_id(),
+            module.identifier().range(),
+            "Module",
+            diagnostics,
+        );
+    }
+
+    fqn_context.push(module.identifier().name());
+    symbol_table.push_scope(&format!("ModuleScope {}", module.identifier().name()));
+
+    for declaration in module.declarations() {
+        gather_node(
+            declaration.as_node_ref(),
+            symbol_table,
+            fqn_context,
+            diagnostics,
+        );
+    }
+
+    symbol_table.pop_scope();
+    fqn_context.pop();
+}
+
+fn gather_interface(
+    interface: &Interface,
+    symbol_table: &mut SymbolTable,
+    fqn_context: &mut FqnContext,
+    diagnostics: &mut Vec<DmDiagnostic>,
+) {
+    let type_symbol = ConcreteTypeSymbol::new(
+        &fqn_context.resolve(interface.identifier().name()),
+        interface.identifier().name(),
+        interface.is_public(),
+        ConcreteTypeSymbolKind::Interface,
+        Some(SourceDefinition::from_identifier(interface.identifier())),
+    );
+    if let Err(symbol_insert_error) =
+        symbol_table.insert_type_symbol(TypeSymbol::Concrete(type_symbol))
+    {
+        handle_insert_error(
+            symbol_insert_error,
+            interface.identifier().name(),
+            interface.identifier().file_id(),
+            interface.identifier().range(),
+            "Interface",
+            diagnostics,
+        );
+    }
+
+    fqn_context.push(interface.identifier().name());
+    symbol_table.push_scope(&format!("InterfaceScope {}", interface.identifier().name()));
+
+    for declaration in interface.declarations() {
+        gather_node(
+            declaration.as_node_ref(),
+            symbol_table,
+            fqn_context,
+            diagnostics,
+        );
+    }
+
+    symbol_table.pop_scope();
+    fqn_context.pop();
+}
+
+fn gather_class(
+    class: &Class,
+    symbol_table: &mut SymbolTable,
+    fqn_context: &mut FqnContext,
+    diagnostics: &mut Vec<DmDiagnostic>,
+) {
+    let class_symbol = ConcreteTypeSymbol::new(
+        &fqn_context.resolve(class.identifier().name()),
+        class.identifier().name(),
+        class.is_public(),
+        ConcreteTypeSymbolKind::Class,
+        Some(SourceDefinition::from_identifier(class.identifier())),
+    );
+    if let Err(symbol_insert_error) =
+        symbol_table.insert_type_symbol(TypeSymbol::Concrete(class_symbol))
+    {
+        handle_insert_error(
+            symbol_insert_error,
+            class.identifier().name(),
+            class.identifier().file_id(),
+            class.identifier().range(),
+            "Class",
+            diagnostics,
+        );
+    }
+
+    fqn_context.push(class.identifier().name());
+    symbol_table.push_scope(&format!("ClassScope {}", class.identifier().name()));
+
+    for declaration in class.class_level_declarations() {
+        gather_node(
+            declaration.as_node_ref(),
+            symbol_table,
+            fqn_context,
+            diagnostics,
+        );
+    }
+
+    symbol_table.pop_scope();
+    fqn_context.pop();
+}
+
+fn gather_function(
+    function: &Function,
+    symbol_table: &mut SymbolTable,
+    fqn_context: &mut FqnContext,
+    diagnostics: &mut Vec<DmDiagnostic>,
+) {
+    let function_symbol = FunctionSymbol::without_parameters_or_return_type(
+        &fqn_context.resolve(function.identifier().name()),
+        function.identifier().name(),
+        function.is_public(),
+        false,
+        Some(SourceDefinition::from_identifier(function.identifier())),
+    );
+    if let Err(insert_error) = symbol_table.insert_function_symbol(function_symbol) {
+        handle_insert_error(
+            insert_error,
+            function.identifier().name(),
+            function.identifier().file_id(),
+            function.identifier().range(),
+            "Function",
+            diagnostics,
+        );
+    }
+    gather_node(
+        function.function_body().as_node_ref(),
+        symbol_table,
+        fqn_context,
+        diagnostics,
+    );
+}
+
+fn gather_function_block_body(
+    function_block_body: &FunctionBlockBody,
+    symbol_table: &mut SymbolTable,
+    fqn_context: &mut FqnContext,
+    diagnostics: &mut Vec<DmDiagnostic>,
+) {
+    symbol_table.push_scope("FunctionBlockBody");
+    gather_node_children(function_block_body, symbol_table, fqn_context, diagnostics);
+    symbol_table.pop_scope();
+}
+
+fn gather_variable_declaration(
+    variable_declaration: &VariableDeclaration,
+    symbol_table: &mut SymbolTable,
+    fqn_context: &mut FqnContext,
+    diagnostics: &mut Vec<DmDiagnostic>,
+) {
+    let variable_symbol = VariableSymbol::new(
+        variable_declaration.identifier().name(),
+        variable_declaration.is_mut(),
+        Some(SourceDefinition::from_identifier(
+            variable_declaration.identifier(),
+        )),
+    );
+    if let Err(insert_error) = symbol_table.insert_variable_symbol(variable_symbol) {
+        handle_insert_error(
+            insert_error,
+            variable_declaration.identifier().name(),
+            variable_declaration.identifier().file_id(),
+            variable_declaration.identifier().range(),
+            "Variable",
+            diagnostics,
+        );
+    }
+    if let Some(expression) = variable_declaration.expression() {
+        gather_node(
+            expression.as_node_ref(),
+            symbol_table,
+            fqn_context,
+            diagnostics,
+        );
+    }
+}
diff --git a/src/name_analysis/mod.rs b/src/name_analysis/mod.rs
index 3a951a1..08fa285 100644
--- a/src/name_analysis/mod.rs
+++ b/src/name_analysis/mod.rs
@@ -27,7 +27,7 @@ use crate::name_analysis::symbol_table::SymbolTable;
 use codespan_reporting::files::Files;
 use std::collections::HashMap;
 
-mod fqn_context;
+pub(self) mod fqn_context;
 mod gather;
 // mod resolve;
 pub mod symbol;
@@ -44,13 +44,7 @@ pub fn analyze_names<'a, F: Files<'a, FileId = usize, Name = String>>(
     // gather symbols
     for compilation_unit in compilation_units.iter_mut() {
         let file_name = files.name(compilation_unit.file_id()).unwrap();
-        gather_compilation_unit(
-            compilation_unit,
-            &file_name,
-            symbol_table,
-            &mut identifier_scope_ids,
-            &mut diagnostics,
-        );
+        gather_compilation_unit(compilation_unit, &file_name, symbol_table, &mut diagnostics);
     }
 
     // resolve symbols
diff --git a/src/name_analysis/symbol/type_symbol.rs b/src/name_analysis/symbol/type_symbol.rs
index 4ae5d2e..9a0cb5b 100644
--- a/src/name_analysis/symbol/type_symbol.rs
+++ b/src/name_analysis/symbol/type_symbol.rs
@@ -28,6 +28,7 @@ pub struct ConcreteTypeSymbol {
     fqn: String,
     declared_name: String,
     is_public: bool,
+    kind: ConcreteTypeSymbolKind,
     source_definition: Option<SourceDefinition>,
 }
 
@@ -36,12 +37,14 @@ impl ConcreteTypeSymbol {
         fqn: &str,
         declared_name: &str,
         is_public: bool,
+        kind: ConcreteTypeSymbolKind,
         source_definition: Option<SourceDefinition>,
     ) -> Self {
         Self {
             fqn: fqn.to_string(),
             declared_name: declared_name.to_string(),
             is_public,
+            kind,
             source_definition
         }
     }
@@ -54,6 +57,10 @@ impl ConcreteTypeSymbol {
         self.is_public
     }
     
+    pub fn kind(&self) -> &ConcreteTypeSymbolKind {
+        &self.kind
+    }
+    
     pub fn declared_name(&self) -> &str {
         &self.declared_name
     }
@@ -69,11 +76,18 @@ impl Debug for ConcreteTypeSymbol {
             .field("fqn", &self.fqn)
             .field("declared_name", &self.declared_name)
             .field("is_public", &self.is_public)
+            .field("kind", &self.kind)
             .field("source_definition", &self.source_definition)
             .finish()
     }
 }
 
+#[derive(Clone, Debug)]
+pub enum ConcreteTypeSymbolKind {
+    Interface,
+    Class
+}
+
 #[derive(Clone)]
 pub struct GenericTypeSymbol {
     declared_name: String,
diff --git a/src/parser/ast.yaml b/src/parser/ast.yaml
index 202edcf..ca177fc 100644
--- a/src/parser/ast.yaml
+++ b/src/parser/ast.yaml
@@ -181,7 +181,7 @@ ReturnType:
 CompilationUnit:
   struct:
     children:
-      - parent_mod:
+      - namespace:
           member:
             optional: true
       - use_statements:
@@ -196,12 +196,12 @@ CompilationUnit:
       - file_id:
           special:
             kind: file_id
-ParentMod:
+Namespace:
   struct:
     children:
-      - mod_kw:
+      - ns_kw:
           skip:
-            rule: Mod
+            rule: Ns
       - fqn:
           member:
             rule: FullyQualifiedName
@@ -253,7 +253,6 @@ ModuleLevelDeclaration:
 InterfaceLevelDeclaration:
   tree_enum:
     rules:
-      - CompanionModule
       - Interface
       - Class
       - InterfaceFunction
@@ -263,7 +262,6 @@ InterfaceLevelDeclaration:
 ClassLevelDeclaration:
   tree_enum:
     rules:
-      - CompanionModule
       - Interface
       - Class
       - Function
@@ -290,21 +288,6 @@ Module:
       - end_kw:
           skip:
             rule: End
-CompanionModule:
-  struct:
-    children:
-      - companion_kw:
-          skip:
-            rule: Companion
-      - mod_kw:
-          skip:
-            rule: Mod
-      - declarations:
-          vec:
-            rule: ModuleLevelDeclaration
-      - end_kw:
-          skip:
-            rule: End
 Interface:
   struct:
     children:
diff --git a/src/parser/deimos.pest b/src/parser/deimos.pest
index aba0983..4c65760 100644
--- a/src/parser/deimos.pest
+++ b/src/parser/deimos.pest
@@ -307,13 +307,13 @@ ReturnType = {
 
 CompilationUnit = {
       SOI
-    ~ ParentMod?
+    ~ Namespace?
     ~ ( UseStatement | ModuleLevelDeclaration )*
     ~ EOI
 }
 
-ParentMod = {
-      Mod
+Namespace = {
+      Ns
     ~ FullyQualifiedName
 }
 
@@ -352,8 +352,7 @@ ModuleLevelDeclaration = {
 }
 
 InterfaceLevelDeclaration = {
-      CompanionModule
-    | Interface
+      Interface
     | Class
     | InterfaceFunction
     | InterfaceDefaultFunction
@@ -362,8 +361,7 @@ InterfaceLevelDeclaration = {
 }
 
 ClassLevelDeclaration = {
-      CompanionModule
-    | Interface
+      Interface
     | Class
     | Function
     | OperatorFunction
@@ -380,13 +378,6 @@ Module = {
     ~ End
 }
 
-CompanionModule = {
-      Companion
-    ~ Mod
-    ~ ModuleLevelDeclaration*
-    ~ End
-}
-
 Interface = {
       Pub?
     ~ IntKw