diff --git a/crates/hir/src/code_model.rs b/crates/hir/src/code_model.rs
index d9b4cdfcef9..e9bb4f5416c 100644
--- a/crates/hir/src/code_model.rs
+++ b/crates/hir/src/code_model.rs
@@ -18,8 +18,8 @@
     type_ref::{Mutability, TypeRef},
     AdtId, AssocContainerId, AssocItemId, AssocItemLoc, AttrDefId, ConstId, ConstParamId,
     DefWithBodyId, EnumId, FunctionId, GenericDefId, HasModule, ImplId, LifetimeParamId,
-    LocalEnumVariantId, LocalFieldId, LocalModuleId, Lookup, ModuleId, StaticId, StructId, TraitId,
-    TypeAliasId, TypeParamId, UnionId,
+    LocalEnumVariantId, LocalFieldId, Lookup, ModuleId, StaticId, StructId, TraitId, TypeAliasId,
+    TypeParamId, UnionId,
 };
 use hir_def::{find_path::PrefixKind, item_scope::ItemInNs, visibility::Visibility};
 use hir_expand::{
@@ -90,8 +90,8 @@ pub fn reverse_dependencies(self, db: &dyn HirDatabase) -> Vec<Crate> {
     }
 
     pub fn root_module(self, db: &dyn HirDatabase) -> Module {
-        let module_id = db.crate_def_map(self.id).root();
-        Module::new(self, module_id)
+        let def_map = db.crate_def_map(self.id);
+        Module { id: def_map.module_id(def_map.root()) }
     }
 
     pub fn root_file(self, db: &dyn HirDatabase) -> FileId {
@@ -275,10 +275,6 @@ pub fn diagnostics(self, db: &dyn HirDatabase, sink: &mut DiagnosticSink) {
 }
 
 impl Module {
-    pub(crate) fn new(krate: Crate, crate_module_id: LocalModuleId) -> Module {
-        Module { id: ModuleId::top_level(krate.id, crate_module_id) }
-    }
-
     /// Name of this module.
     pub fn name(self, db: &dyn HirDatabase) -> Option<Name> {
         let def_map = self.id.def_map(db.upcast());
@@ -302,7 +298,7 @@ pub fn krate(self) -> Crate {
     /// in the module tree of any target in `Cargo.toml`.
     pub fn crate_root(self, db: &dyn HirDatabase) -> Module {
         let def_map = db.crate_def_map(self.id.krate());
-        self.with_module_id(def_map.root())
+        Module { id: def_map.module_id(def_map.root()) }
     }
 
     /// Iterates over all child modules.
@@ -311,7 +307,7 @@ pub fn children(self, db: &dyn HirDatabase) -> impl Iterator<Item = Module> {
         let children = def_map[self.id.local_id]
             .children
             .iter()
-            .map(|(_, module_id)| self.with_module_id(*module_id))
+            .map(|(_, module_id)| Module { id: def_map.module_id(*module_id) })
             .collect::<Vec<_>>();
         children.into_iter()
     }
@@ -321,7 +317,7 @@ pub fn parent(self, db: &dyn HirDatabase) -> Option<Module> {
         // FIXME: handle block expressions as modules (their parent is in a different DefMap)
         let def_map = self.id.def_map(db.upcast());
         let parent_id = def_map[self.id.local_id].parent?;
-        Some(self.with_module_id(parent_id))
+        Some(Module { id: def_map.module_id(parent_id) })
     }
 
     pub fn path_to_root(self, db: &dyn HirDatabase) -> Vec<Module> {
@@ -406,10 +402,6 @@ pub fn impl_defs(self, db: &dyn HirDatabase) -> Vec<Impl> {
         def_map[self.id.local_id].scope.impls().map(Impl::from).collect()
     }
 
-    pub(crate) fn with_module_id(self, module_id: LocalModuleId) -> Module {
-        Module::new(self.krate(), module_id)
-    }
-
     /// Finds a path that can be used to refer to the given item from within
     /// this module, if possible.
     pub fn find_use_path(self, db: &dyn DefDatabase, item: impl Into<ItemInNs>) -> Option<ModPath> {
@@ -1013,8 +1005,9 @@ impl MacroDef {
     /// early, in `hir_expand`, where modules simply do not exist yet.
     pub fn module(self, db: &dyn HirDatabase) -> Option<Module> {
         let krate = self.id.krate;
-        let module_id = db.crate_def_map(krate).root();
-        Some(Module::new(Crate { id: krate }, module_id))
+        let def_map = db.crate_def_map(krate);
+        let module_id = def_map.root();
+        Some(Module { id: def_map.module_id(module_id) })
     }
 
     /// XXX: this parses the file
diff --git a/crates/hir/src/semantics/source_to_def.rs b/crates/hir/src/semantics/source_to_def.rs
index faede326994..6c612ee8635 100644
--- a/crates/hir/src/semantics/source_to_def.rs
+++ b/crates/hir/src/semantics/source_to_def.rs
@@ -30,13 +30,12 @@ pub(super) struct SourceToDefCtx<'a, 'b> {
 impl SourceToDefCtx<'_, '_> {
     pub(super) fn file_to_def(&mut self, file: FileId) -> Option<ModuleId> {
         let _p = profile::span("SourceBinder::to_module_def");
-        let (krate, local_id) = self.db.relevant_crates(file).iter().find_map(|&crate_id| {
+        self.db.relevant_crates(file).iter().find_map(|&crate_id| {
             // FIXME: inner items
             let crate_def_map = self.db.crate_def_map(crate_id);
             let local_id = crate_def_map.modules_for_file(file).next()?;
-            Some((crate_id, local_id))
-        })?;
-        Some(ModuleId::top_level(krate, local_id))
+            Some(crate_def_map.module_id(local_id))
+        })
     }
 
     pub(super) fn module_to_def(&mut self, src: InFile<ast::Module>) -> Option<ModuleId> {
@@ -63,8 +62,7 @@ pub(super) fn module_to_def(&mut self, src: InFile<ast::Module>) -> Option<Modul
         let child_name = src.value.name()?.as_name();
         let def_map = parent_module.def_map(self.db.upcast());
         let child_id = *def_map[parent_module.local_id].children.get(&child_name)?;
-        // FIXME: handle block expression modules
-        Some(ModuleId::top_level(parent_module.krate(), child_id))
+        Some(def_map.module_id(child_id))
     }
 
     pub(super) fn trait_to_def(&mut self, src: InFile<ast::Trait>) -> Option<TraitId> {
diff --git a/crates/hir_def/src/find_path.rs b/crates/hir_def/src/find_path.rs
index c01b6daf2c0..94a1d567d88 100644
--- a/crates/hir_def/src/find_path.rs
+++ b/crates/hir_def/src/find_path.rs
@@ -53,12 +53,8 @@ fn check_self_super(def_map: &DefMap, item: ItemInNs, from: ModuleId) -> Option<
         Some(ModPath::from_segments(PathKind::Super(0), Vec::new()))
     } else if let Some(parent_id) = def_map[from.local_id].parent {
         // - if the item is the parent module, use `super` (this is not used recursively, since `super::super` is ugly)
-        if item
-            == ItemInNs::Types(ModuleDefId::ModuleId(ModuleId {
-                krate: from.krate,
-                local_id: parent_id,
-            }))
-        {
+        let parent_id = def_map.module_id(parent_id);
+        if item == ItemInNs::Types(ModuleDefId::ModuleId(parent_id)) {
             Some(ModPath::from_segments(PathKind::Super(1), Vec::new()))
         } else {
             None
@@ -120,12 +116,8 @@ fn find_path_inner(
     }
 
     // - if the item is the crate root, return `crate`
-    if item
-        == ItemInNs::Types(ModuleDefId::ModuleId(ModuleId {
-            krate: from.krate,
-            local_id: def_map.root(),
-        }))
-    {
+    let root = def_map.module_id(def_map.root());
+    if item == ItemInNs::Types(ModuleDefId::ModuleId(root)) {
         return Some(ModPath::from_segments(PathKind::Crate, Vec::new()));
     }
 
@@ -175,7 +167,7 @@ fn find_path_inner(
 
     // - otherwise, look for modules containing (reexporting) it and import it from one of those
 
-    let crate_root = ModuleId { local_id: def_map.root(), krate: from.krate };
+    let crate_root = def_map.module_id(def_map.root());
     let crate_attrs = db.attrs(crate_root.into());
     let prefer_no_std = crate_attrs.by_key("no_std").exists();
     let mut best_path = None;
@@ -288,14 +280,11 @@ fn find_local_import_locations(
     // Compute the initial worklist. We start with all direct child modules of `from` as well as all
     // of its (recursive) parent modules.
     let data = &def_map[from.local_id];
-    let mut worklist = data
-        .children
-        .values()
-        .map(|child| ModuleId { krate: from.krate, local_id: *child })
-        .collect::<Vec<_>>();
+    let mut worklist =
+        data.children.values().map(|child| def_map.module_id(*child)).collect::<Vec<_>>();
     let mut parent = data.parent;
     while let Some(p) = parent {
-        worklist.push(ModuleId { krate: from.krate, local_id: p });
+        worklist.push(def_map.module_id(p));
         parent = def_map[p].parent;
     }
 
diff --git a/crates/hir_def/src/import_map.rs b/crates/hir_def/src/import_map.rs
index 0b783044564..0a3dc79564d 100644
--- a/crates/hir_def/src/import_map.rs
+++ b/crates/hir_def/src/import_map.rs
@@ -75,7 +75,7 @@ pub fn import_map_query(db: &dyn DefDatabase, krate: CrateId) -> Arc<Self> {
 
         // We look only into modules that are public(ly reexported), starting with the crate root.
         let empty = ImportPath { segments: vec![] };
-        let root = ModuleId { krate, local_id: def_map.root() };
+        let root = def_map.module_id(def_map.root());
         let mut worklist = vec![(root, empty)];
         while let Some((module, mod_path)) = worklist.pop() {
             let ext_def_map;
diff --git a/crates/hir_def/src/lib.rs b/crates/hir_def/src/lib.rs
index c8dbb2aeb3b..cf09ebd3f08 100644
--- a/crates/hir_def/src/lib.rs
+++ b/crates/hir_def/src/lib.rs
@@ -78,10 +78,6 @@ pub struct ModuleId {
 }
 
 impl ModuleId {
-    pub fn top_level(krate: CrateId, local_id: LocalModuleId) -> Self {
-        Self { krate, local_id }
-    }
-
     pub fn def_map(&self, db: &dyn db::DefDatabase) -> Arc<DefMap> {
         db.crate_def_map(self.krate)
     }
diff --git a/crates/hir_def/src/nameres.rs b/crates/hir_def/src/nameres.rs
index bd3ea9b8b1b..4fbbecb386d 100644
--- a/crates/hir_def/src/nameres.rs
+++ b/crates/hir_def/src/nameres.rs
@@ -265,6 +265,10 @@ pub(crate) fn extern_prelude(&self) -> impl Iterator<Item = (&Name, &ModuleDefId
         self.extern_prelude.iter()
     }
 
+    pub fn module_id(&self, local_id: LocalModuleId) -> ModuleId {
+        ModuleId { krate: self.krate, local_id }
+    }
+
     pub(crate) fn resolve_path(
         &self,
         db: &dyn DefDatabase,
diff --git a/crates/hir_def/src/nameres/collector.rs b/crates/hir_def/src/nameres/collector.rs
index adfcf879a44..393170b32f1 100644
--- a/crates/hir_def/src/nameres/collector.rs
+++ b/crates/hir_def/src/nameres/collector.rs
@@ -37,8 +37,8 @@
     per_ns::PerNs,
     visibility::{RawVisibility, Visibility},
     AdtId, AsMacroCall, AstId, AstIdWithPath, ConstLoc, ContainerId, EnumLoc, EnumVariantId,
-    FunctionLoc, ImplLoc, Intern, LocalModuleId, ModuleDefId, ModuleId, StaticLoc, StructLoc,
-    TraitLoc, TypeAliasLoc, UnionLoc,
+    FunctionLoc, ImplLoc, Intern, LocalModuleId, ModuleDefId, StaticLoc, StructLoc, TraitLoc,
+    TypeAliasLoc, UnionLoc,
 };
 
 const GLOB_RECURSION_LIMIT: usize = 100;
@@ -56,10 +56,9 @@ pub(super) fn collect_defs(
     for dep in &crate_graph[def_map.krate].dependencies {
         log::debug!("crate dep {:?} -> {:?}", dep.name, dep.crate_id);
         let dep_def_map = db.crate_def_map(dep.crate_id);
-        def_map.extern_prelude.insert(
-            dep.as_name(),
-            ModuleId { krate: dep.crate_id, local_id: dep_def_map.root }.into(),
-        );
+        def_map
+            .extern_prelude
+            .insert(dep.as_name(), dep_def_map.module_id(dep_def_map.root).into());
 
         // look for the prelude
         // If the dependency defines a prelude, we overwrite an already defined
@@ -332,11 +331,9 @@ fn collect(&mut self) {
             // exported in type/value namespace. This function reduces the visibility of all items
             // in the crate root that aren't proc macros.
             let root = self.def_map.root;
+            let module_id = self.def_map.module_id(root);
             let root = &mut self.def_map.modules[root];
-            root.scope.censor_non_proc_macros(ModuleId {
-                krate: self.def_map.krate,
-                local_id: self.def_map.root,
-            });
+            root.scope.censor_non_proc_macros(module_id);
         }
     }
 
@@ -1029,8 +1026,7 @@ fn collect(&mut self, items: &[ModItem]) {
                     continue;
                 }
             }
-            let module =
-                ModuleId { krate: self.def_collector.def_map.krate, local_id: self.module_id };
+            let module = self.def_collector.def_map.module_id(self.module_id);
             let container = ContainerId::ModuleId(module);
 
             let mut def = None;
@@ -1097,10 +1093,7 @@ fn collect(&mut self, items: &[ModItem]) {
                     }
                 }
                 ModItem::Impl(imp) => {
-                    let module = ModuleId {
-                        krate: self.def_collector.def_map.krate,
-                        local_id: self.module_id,
-                    };
+                    let module = self.def_collector.def_map.module_id(self.module_id);
                     let container = ContainerId::ModuleId(module);
                     let impl_id = ImplLoc { container, id: ItemTreeId::new(self.file_id, imp) }
                         .intern(self.def_collector.db);
@@ -1343,7 +1336,7 @@ fn push_child_module(
             modules[res].scope.define_legacy_macro(name, mac)
         }
         modules[self.module_id].children.insert(name.clone(), res);
-        let module = ModuleId { krate: self.def_collector.def_map.krate, local_id: res };
+        let module = self.def_collector.def_map.module_id(res);
         let def: ModuleDefId = module.into();
         self.def_collector.def_map.modules[self.module_id].scope.define_def(def);
         self.def_collector.update(
diff --git a/crates/hir_def/src/nameres/path_resolution.rs b/crates/hir_def/src/nameres/path_resolution.rs
index 7b5fe24a7c5..c1eded5f2b1 100644
--- a/crates/hir_def/src/nameres/path_resolution.rs
+++ b/crates/hir_def/src/nameres/path_resolution.rs
@@ -24,7 +24,7 @@
     path::{ModPath, PathKind},
     per_ns::PerNs,
     visibility::{RawVisibility, Visibility},
-    AdtId, CrateId, EnumVariantId, LocalModuleId, ModuleDefId, ModuleId,
+    AdtId, CrateId, EnumVariantId, LocalModuleId, ModuleDefId,
 };
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -66,10 +66,7 @@ impl DefMap {
     pub(super) fn resolve_name_in_extern_prelude(&self, name: &Name) -> PerNs {
         if name == &name!(self) {
             mark::hit!(extern_crate_self_as);
-            return PerNs::types(
-                ModuleId { krate: self.krate, local_id: self.root }.into(),
-                Visibility::Public,
-            );
+            return PerNs::types(self.module_id(self.root).into(), Visibility::Public);
         }
         self.extern_prelude
             .get(name)
@@ -154,21 +151,15 @@ pub(super) fn resolve_path_fp_with_macro_single(
             PathKind::DollarCrate(krate) => {
                 if krate == self.krate {
                     mark::hit!(macro_dollar_crate_self);
-                    PerNs::types(
-                        ModuleId { krate: self.krate, local_id: self.root }.into(),
-                        Visibility::Public,
-                    )
+                    PerNs::types(self.module_id(self.root).into(), Visibility::Public)
                 } else {
                     let def_map = db.crate_def_map(krate);
-                    let module = ModuleId { krate, local_id: def_map.root };
+                    let module = def_map.module_id(def_map.root);
                     mark::hit!(macro_dollar_crate_other);
                     PerNs::types(module.into(), Visibility::Public)
                 }
             }
-            PathKind::Crate => PerNs::types(
-                ModuleId { krate: self.krate, local_id: self.root }.into(),
-                Visibility::Public,
-            ),
+            PathKind::Crate => PerNs::types(self.module_id(self.root).into(), Visibility::Public),
             // plain import or absolute path in 2015: crate-relative with
             // fallback to extern prelude (with the simplification in
             // rust-lang/rust#57745)
@@ -205,10 +196,7 @@ pub(super) fn resolve_path_fp_with_macro_single(
                 let m = successors(Some(original_module), |m| self.modules[*m].parent)
                     .nth(lvl as usize);
                 if let Some(local_id) = m {
-                    PerNs::types(
-                        ModuleId { krate: self.krate, local_id }.into(),
-                        Visibility::Public,
-                    )
+                    PerNs::types(self.module_id(local_id).into(), Visibility::Public)
                 } else {
                     log::debug!("super path in root module");
                     return ResolvePathResult::empty(ReachedFixedPoint::Yes);
diff --git a/crates/hir_def/src/resolver.rs b/crates/hir_def/src/resolver.rs
index 130c074f088..9021ea7125c 100644
--- a/crates/hir_def/src/resolver.rs
+++ b/crates/hir_def/src/resolver.rs
@@ -459,7 +459,7 @@ fn resolve_local_macro_def(&self, path: &ModPath) -> Option<MacroDefId> {
 
     pub fn module(&self) -> Option<ModuleId> {
         let (def_map, local_id) = self.module_scope()?;
-        Some(ModuleId { krate: def_map.krate(), local_id })
+        Some(def_map.module_id(local_id))
     }
 
     pub fn krate(&self) -> Option<CrateId> {
diff --git a/crates/hir_def/src/test_db.rs b/crates/hir_def/src/test_db.rs
index 4ff219fb702..c4e36eda5e5 100644
--- a/crates/hir_def/src/test_db.rs
+++ b/crates/hir_def/src/test_db.rs
@@ -15,7 +15,7 @@
 use syntax::{TextRange, TextSize};
 use test_utils::extract_annotations;
 
-use crate::{db::DefDatabase, ModuleDefId};
+use crate::{db::DefDatabase, ModuleDefId, ModuleId};
 
 #[salsa::database(
     base_db::SourceDatabaseExtStorage,
@@ -72,12 +72,12 @@ fn relevant_crates(&self, file_id: FileId) -> Arc<FxHashSet<CrateId>> {
 }
 
 impl TestDB {
-    pub(crate) fn module_for_file(&self, file_id: FileId) -> crate::ModuleId {
+    pub(crate) fn module_for_file(&self, file_id: FileId) -> ModuleId {
         for &krate in self.relevant_crates(file_id).iter() {
             let crate_def_map = self.crate_def_map(krate);
             for (local_id, data) in crate_def_map.modules() {
                 if data.origin.file_id() == Some(file_id) {
-                    return crate::ModuleId { krate, local_id };
+                    return crate_def_map.module_id(local_id);
                 }
             }
         }
diff --git a/crates/hir_ty/src/test_db.rs b/crates/hir_ty/src/test_db.rs
index 09696fcf464..381b98ba808 100644
--- a/crates/hir_ty/src/test_db.rs
+++ b/crates/hir_ty/src/test_db.rs
@@ -83,7 +83,7 @@ pub(crate) fn module_for_file(&self, file_id: FileId) -> ModuleId {
             let crate_def_map = self.crate_def_map(krate);
             for (local_id, data) in crate_def_map.modules() {
                 if data.origin.file_id() == Some(file_id) {
-                    return ModuleId::top_level(krate, local_id);
+                    return crate_def_map.module_id(local_id);
                 }
             }
         }