diff --git a/crates/ra_analysis/src/db.rs b/crates/ra_analysis/src/db.rs
index 042dde1aca9..99d40a2690d 100644
--- a/crates/ra_analysis/src/db.rs
+++ b/crates/ra_analysis/src/db.rs
@@ -76,12 +76,18 @@ salsa::query_group! {
     }
 }
 
-#[derive(Default, Debug, PartialEq, Eq)]
+#[derive(Default, Debug, Eq)]
 pub(crate) struct FileSet {
     pub(crate) files: FxHashSet<FileId>,
     pub(crate) resolver: FileResolverImp,
 }
 
+impl PartialEq for FileSet {
+    fn eq(&self, other: &FileSet) -> bool {
+        self.files == other.files && self.resolver == other.resolver
+    }
+}
+
 impl Hash for FileSet {
     fn hash<H: Hasher>(&self, hasher: &mut H) {
         let mut files = self.files.iter().cloned().collect::<Vec<_>>();