diff --git a/crates/libanalysis/src/lib.rs b/crates/libanalysis/src/lib.rs
index 85c23e4d970..9429f8f5522 100644
--- a/crates/libanalysis/src/lib.rs
+++ b/crates/libanalysis/src/lib.rs
@@ -15,6 +15,8 @@
 use rayon::prelude::*;
 
 use std::{
+    fmt,
+    path::Path,
     sync::{
         Arc,
         atomic::{AtomicUsize, Ordering::SeqCst},
@@ -35,15 +37,24 @@
 pub type Result<T> = ::std::result::Result<T, ::failure::Error>;
 const INDEXING_THRESHOLD: usize = 128;
 
+pub type FileResolver = dyn Fn(FileId, &Path) -> Option<FileId> + Send + Sync;
+
 pub struct WorldState {
     data: Arc<WorldData>
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone)]
 pub struct World {
+    file_resolver: Arc<FileResolver>,
     data: Arc<WorldData>,
 }
 
+impl fmt::Debug for World {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        (&*self.data).fmt(f)
+    }
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub struct FileId(pub u32);
 
@@ -54,8 +65,11 @@ pub fn new() -> WorldState {
         }
     }
 
-    pub fn snapshot(&self) -> World {
-        World { data: self.data.clone() }
+    pub fn snapshot(&self, file_resolver: impl Fn(FileId, &Path) -> Option<FileId> + 'static + Send + Sync) -> World {
+        World {
+            file_resolver: Arc::new(file_resolver),
+            data: self.data.clone()
+        }
     }
 
     pub fn change_file(&mut self, file_id: FileId, text: Option<String>) {
@@ -134,6 +148,10 @@ pub fn approximately_resolve_symbol<'a>(
         Ok(self.world_symbols(query).collect())
     }
 
+    fn resolve_relative_path(&self, id: FileId, path: &Path) -> Option<FileId> {
+        (self.file_resolver)(id, path)
+    }
+
     fn reindex(&self) {
         let data = &*self.data;
         let unindexed = data.unindexed.load(SeqCst);
diff --git a/crates/server/src/main_loop/mod.rs b/crates/server/src/main_loop/mod.rs
index 1fbcc7d1f85..a8340df5911 100644
--- a/crates/server/src/main_loop/mod.rs
+++ b/crates/server/src/main_loop/mod.rs
@@ -167,7 +167,10 @@ fn on_request(
     dispatch::handle_request::<req::ExecuteCommand, _>(&mut req, |params, resp| {
         io.send(RawMsg::Response(resp.into_response(Ok(None))?));
 
-        let world = world.snapshot();
+        let world = world.snapshot({
+            let pm = path_map.clone();
+            move |id, path| pm.resolve(id, path)
+        });
         let path_map = path_map.clone();
         let sender = sender.clone();
         pool.execute(move || {
@@ -234,7 +237,14 @@ fn on_notification(
         mem_map.insert(file_id, None);
         world.change_file(file_id, Some(params.text_document.text));
         update_file_notifications_on_threadpool(
-            pool, world.snapshot(), path_map.clone(), sender.clone(), uri,
+            pool,
+            world.snapshot({
+                let pm = path_map.clone();
+                move |id, path| pm.resolve(id, path)
+            }),
+            path_map.clone(),
+            sender.clone(),
+            uri,
         );
         Ok(())
     })?;
@@ -245,7 +255,14 @@ fn on_notification(
             .text;
         world.change_file(file_id, Some(text));
         update_file_notifications_on_threadpool(
-            pool, world.snapshot(), path_map.clone(), sender.clone(), params.text_document.uri,
+            pool,
+            world.snapshot({
+                let pm = path_map.clone();
+                move |id, path| pm.resolve(id, path)
+            }),
+            path_map.clone(),
+            sender.clone(),
+            params.text_document.uri,
         );
         Ok(())
     })?;
@@ -281,7 +298,10 @@ fn handle_request_on_threadpool<R: req::ClientRequest>(
 ) -> Result<()>
 {
     dispatch::handle_request::<R, _>(req, |params, resp| {
-        let world = world.snapshot();
+        let world = world.snapshot({
+            let pm = path_map.clone();
+            move |id, path| pm.resolve(id, path)
+        });
         let path_map = path_map.clone();
         let sender = sender.clone();
         pool.execute(move || {
diff --git a/crates/server/src/path_map.rs b/crates/server/src/path_map.rs
index 2454ba05fed..e198e165deb 100644
--- a/crates/server/src/path_map.rs
+++ b/crates/server/src/path_map.rs
@@ -34,6 +34,11 @@ pub fn get_path(&self, id: FileId) -> &Path {
             .as_path()
     }
 
+    pub fn resolve(&self, id: FileId, relpath: &Path) -> Option<FileId> {
+        let path = self.get_path(id).join(relpath);
+        self.get_id(&path)
+    }
+
     fn insert(&mut self, path: PathBuf, id: FileId) {
         self.path2id.insert(path.clone(), id);
         self.id2path.insert(id, path.clone());