diff --git a/crates/ra_hir/src/module_tree.rs b/crates/ra_hir/src/module_tree.rs
index d1dc3fa4b7..893c375b55 100644
--- a/crates/ra_hir/src/module_tree.rs
+++ b/crates/ra_hir/src/module_tree.rs
@@ -172,6 +172,7 @@ impl ModuleTree {
         file_id: HirFileId,
         decl_id: Option<SourceFileItemId>,
     ) -> ModuleId {
+        let is_root = parent.is_none();
         let id = self.alloc_mod(ModuleData {
             file_id,
             decl_id,
@@ -191,7 +192,7 @@ impl ModuleTree {
             });
 
             let (points_to, problem) = if sub.is_declaration {
-                let (points_to, problem) = resolve_submodule(db, file_id, &sub.name);
+                let (points_to, problem) = resolve_submodule(db, file_id, &sub.name, is_root);
                 let points_to = points_to
                     .into_iter()
                     .map(|file_id| {
@@ -295,6 +296,7 @@ fn resolve_submodule(
     db: &impl HirDatabase,
     file_id: HirFileId,
     name: &Name,
+    is_root: bool,
 ) -> (Vec<FileId>, Option<Problem>) {
     // FIXME: handle submodules of inline modules properly
     let file_id = file_id.original_file(db);
@@ -303,7 +305,7 @@ fn resolve_submodule(
     let root = RelativePathBuf::default();
     let dir_path = path.parent().unwrap_or(&root);
     let mod_name = path.file_stem().unwrap_or("unknown");
-    let is_dir_owner = mod_name == "mod" || mod_name == "lib" || mod_name == "main";
+    let is_dir_owner = is_root || mod_name == "mod";
 
     let file_mod = dir_path.join(format!("{}.rs", name));
     let dir_mod = dir_path.join(format!("{}/mod.rs", name));
diff --git a/crates/ra_hir/src/nameres/tests.rs b/crates/ra_hir/src/nameres/tests.rs
index e72781f512..3d420467c1 100644
--- a/crates/ra_hir/src/nameres/tests.rs
+++ b/crates/ra_hir/src/nameres/tests.rs
@@ -19,6 +19,20 @@ fn item_map(fixture: &str) -> (Arc<ItemMap>, ModuleId) {
     (db.item_map(krate.crate_id), module_id)
 }
 
+/// Sets the crate root to the file of the cursor marker
+fn item_map_custom_crate_root(fixture: &str) -> (Arc<ItemMap>, ModuleId) {
+    let (mut db, pos) = MockDatabase::with_position(fixture);
+
+    let mut crate_graph = CrateGraph::default();
+    crate_graph.add_crate_root(pos.file_id);
+    db.set_crate_graph(Arc::new(crate_graph));
+
+    let module = crate::source_binder::module_from_position(&db, pos).unwrap();
+    let krate = module.krate(&db).unwrap();
+    let module_id = module.module_id;
+    (db.item_map(krate.crate_id), module_id)
+}
+
 fn check_module_item_map(map: &ItemMap, module_id: ModuleId, expected: &str) {
     let mut lines = map[module_id]
         .items
@@ -133,6 +147,28 @@ fn re_exports() {
     );
 }
 
+#[test]
+fn module_resolution_works_for_non_standard_filenames() {
+    let (item_map, module_id) = item_map_custom_crate_root(
+        "
+        //- /my_library.rs
+        mod foo;
+        use self::foo::Bar;
+        <|>
+        //- /foo/mod.rs
+        pub struct Bar;
+    ",
+    );
+    check_module_item_map(
+        &item_map,
+        module_id,
+        "
+            Bar: t v
+            foo: t
+        ",
+    );
+}
+
 #[test]
 fn name_res_works_for_broken_modules() {
     covers!(name_res_works_for_broken_modules);
diff --git a/crates/ra_ide_api/tests/test/main.rs b/crates/ra_ide_api/tests/test/main.rs
index 7560751909..c2cb38f7e9 100644
--- a/crates/ra_ide_api/tests/test/main.rs
+++ b/crates/ra_ide_api/tests/test/main.rs
@@ -1,9 +1,9 @@
+use insta::assert_debug_snapshot_matches;
 use ra_ide_api::{
-    AnalysisChange,
-    CrateGraph, FileId, mock_analysis::{MockAnalysis, single_file, single_file_with_position}, Query,
+    mock_analysis::{single_file, single_file_with_position, MockAnalysis},
+    AnalysisChange, CrateGraph, FileId, Query,
 };
 use ra_syntax::TextRange;
-use insta::assert_debug_snapshot_matches;
 
 #[test]
 fn test_unresolved_module_diagnostic() {
@@ -26,12 +26,12 @@ fn test_resolve_crate_root() {
         "
         //- /bar.rs
         mod foo;
-        //- /bar/foo.rs
-        // emtpy <|>
+        //- /foo.rs
+        // empty <|>
     ",
     );
     let root_file = mock.id_of("/bar.rs");
-    let mod_file = mock.id_of("/bar/foo.rs");
+    let mod_file = mock.id_of("/foo.rs");
     let mut host = mock.analysis_host();
     assert!(host.analysis().crate_for(mod_file).unwrap().is_empty());
 
diff --git a/crates/ra_syntax/src/algo.rs b/crates/ra_syntax/src/algo.rs
index 45747e21d4..99b0983b0d 100644
--- a/crates/ra_syntax/src/algo.rs
+++ b/crates/ra_syntax/src/algo.rs
@@ -17,14 +17,14 @@ pub fn find_leaf_at_offset(node: &SyntaxNode, offset: TextUnit) -> LeafAtOffset<
 }
 
 /// Finds a node of specific Ast type at offset. Note that this is slightly
-/// impercise: if the cursor is strictly betwen two nodes of the desired type,
+/// imprecise: if the cursor is strictly between two nodes of the desired type,
 /// as in
 ///
 /// ```no-run
 /// struct Foo {}|struct Bar;
 /// ```
 ///
-/// then the left node will be silently prefered.
+/// then the left node will be silently preferred.
 pub fn find_node_at_offset<N: AstNode>(syntax: &SyntaxNode, offset: TextUnit) -> Option<&N> {
     find_leaf_at_offset(syntax, offset).find_map(|leaf| leaf.ancestors().find_map(N::cast))
 }