diff --git a/crates/ra_hir/src/from_source.rs b/crates/ra_hir/src/from_source.rs
index f80d8eb5f1..a137aeb909 100644
--- a/crates/ra_hir/src/from_source.rs
+++ b/crates/ra_hir/src/from_source.rs
@@ -181,7 +181,6 @@ impl Module {
     ) -> Option<Self> {
         let decl_id = match src.ast {
             ModuleSource::Module(ref module) => {
-                assert!(!module.has_semi());
                 let ast_id_map = db.ast_id_map(src.file_id);
                 let item_id = ast_id_map.ast_id(module).with_file_id(src.file_id);
                 Some(item_id)
diff --git a/crates/ra_ide_api/src/references.rs b/crates/ra_ide_api/src/references.rs
index 0f1ac57fc1..3d647d2cbc 100644
--- a/crates/ra_ide_api/src/references.rs
+++ b/crates/ra_ide_api/src/references.rs
@@ -232,7 +232,7 @@ mod tests {
     }
 
     #[test]
-    fn test_find_all_refs_modules() {
+    fn test_find_all_refs_two_modules() {
         let code = r#"
             //- /lib.rs
             pub mod foo;
@@ -270,6 +270,33 @@ mod tests {
         assert_eq!(refs.len(), 3);
     }
 
+
+    // `mod foo;` is not in the results because `foo` is an `ast::Name`.
+    // So, there are two references: the first one is a definition of the `foo` module, 
+    // which is the whole `foo.rs`, and the second one is in `use foo::Foo`.
+    #[test]
+    fn test_find_all_refs_decl_module() {
+        let code = r#"
+            //- /lib.rs
+            mod foo<|>;
+
+            use foo::Foo;
+
+            fn f() {
+                let i = Foo { n: 5 };
+            }
+
+            //- /foo.rs
+            pub struct Foo {
+                pub n: u32,
+            }
+        "#;
+
+        let (analysis, pos) = analysis_and_position(code);
+        let refs = analysis.find_all_refs(pos).unwrap().unwrap();
+        assert_eq!(refs.len(), 2);
+    }
+
     fn get_all_refs(text: &str) -> ReferenceSearchResult {
         let (analysis, position) = single_file_with_position(text);
         analysis.find_all_refs(position).unwrap().unwrap()
diff --git a/crates/ra_ide_api/src/references/classify.rs b/crates/ra_ide_api/src/references/classify.rs
index 93e079cccb..ac9cf34eb0 100644
--- a/crates/ra_ide_api/src/references/classify.rs
+++ b/crates/ra_ide_api/src/references/classify.rs
@@ -31,9 +31,16 @@ pub(crate) fn classify_name(
                 Some(from_struct_field(db, field))
             },
             ast::Module(it) => {
-                let ast = hir::ModuleSource::Module(it);
-                let src = hir::Source { file_id, ast };
-                let def = hir::Module::from_definition(db, src)?;
+                let def = {
+                    if !it.has_semi() {
+                        let ast = hir::ModuleSource::Module(it);
+                        let src = hir::Source { file_id, ast };
+                        hir::Module::from_definition(db, src)
+                    } else {
+                        let src = hir::Source { file_id, ast: it };
+                        hir::Module::from_declaration(db, src)
+                    }
+                }?;
                 Some(from_module_def(db, def.into(), None))
             },
             ast::StructDef(it) => {
diff --git a/crates/ra_ide_api/src/references/search_scope.rs b/crates/ra_ide_api/src/references/search_scope.rs
index 680988a214..d2c966b4f3 100644
--- a/crates/ra_ide_api/src/references/search_scope.rs
+++ b/crates/ra_ide_api/src/references/search_scope.rs
@@ -1,5 +1,7 @@
 //! FIXME: write short doc here
 
+use std::collections::HashSet;
+
 use hir::{DefWithBody, HasSource, ModuleSource};
 use ra_db::{FileId, SourceDatabase, SourceDatabaseExt};
 use ra_syntax::{AstNode, TextRange};
@@ -9,7 +11,7 @@ use crate::db::RootDatabase;
 use super::{NameDefinition, NameKind};
 
 impl NameDefinition {
-    pub(crate) fn search_scope(&self, db: &RootDatabase) -> Vec<(FileId, Option<TextRange>)> {
+    pub(crate) fn search_scope(&self, db: &RootDatabase) -> HashSet<(FileId, Option<TextRange>)> {
         let module_src = self.container.definition_source(db);
         let file_id = module_src.file_id.original_file(db);
 
@@ -19,13 +21,13 @@ impl NameDefinition {
                 DefWithBody::Const(c) => c.source(db).ast.syntax().text_range(),
                 DefWithBody::Static(s) => s.source(db).ast.syntax().text_range(),
             };
-            return vec![(file_id, Some(range))];
+            return [(file_id, Some(range))].iter().cloned().collect();
         }
 
         if let Some(ref vis) = self.visibility {
             let source_root_id = db.file_source_root(file_id);
             let source_root = db.source_root(source_root_id);
-            let mut files = source_root.walk().map(|id| (id.into(), None)).collect::<Vec<_>>();
+            let mut files = source_root.walk().map(|id| (id.into(), None)).collect::<HashSet<_>>();
 
             if vis.syntax().to_string().as_str() == "pub(crate)" {
                 return files;
@@ -54,6 +56,6 @@ impl NameDefinition {
             ModuleSource::Module(m) => Some(m.syntax().text_range()),
             ModuleSource::SourceFile(_) => None,
         };
-        vec![(file_id, range)]
+        [(file_id, range)].iter().cloned().collect()
     }
 }