diff --git a/crates/ra_batch/src/lib.rs b/crates/ra_batch/src/lib.rs
index 02ea893065..c59821f446 100644
--- a/crates/ra_batch/src/lib.rs
+++ b/crates/ra_batch/src/lib.rs
@@ -43,8 +43,12 @@ fn vfs_root_to_id(r: ra_vfs::VfsRoot) -> SourceRootId {
 impl BatchDatabase {
     pub fn load(crate_graph: CrateGraph, vfs: &mut Vfs) -> BatchDatabase {
         let mut db = BatchDatabase { runtime: salsa::Runtime::default() };
-        db.query_mut(ra_db::ParseQuery).set_lru_capacity(128);
-        db.query_mut(ra_hir::db::ParseMacroQuery).set_lru_capacity(128);
+        let lru_cap = std::env::var("RA_LRU_CAP")
+            .ok()
+            .and_then(|it| it.parse::<usize>().ok())
+            .unwrap_or(ra_db::DEFAULT_LRU_CAP);
+        db.query_mut(ra_db::ParseQuery).set_lru_capacity(lru_cap);
+        db.query_mut(ra_hir::db::ParseMacroQuery).set_lru_capacity(lru_cap);
         db.set_crate_graph(Arc::new(crate_graph));
 
         // wait until Vfs has loaded all roots
diff --git a/crates/ra_db/src/lib.rs b/crates/ra_db/src/lib.rs
index 7c49c585bc..f08616100d 100644
--- a/crates/ra_db/src/lib.rs
+++ b/crates/ra_db/src/lib.rs
@@ -65,6 +65,8 @@ pub struct FileRange {
     pub range: TextRange,
 }
 
+pub const DEFAULT_LRU_CAP: usize = 128;
+
 /// Database which stores all significant input facts: source code and project
 /// model. Everything else in rust-analyzer is derived from these queries.
 #[salsa::query_group(SourceDatabaseStorage)]
diff --git a/crates/ra_ide_api/src/db.rs b/crates/ra_ide_api/src/db.rs
index 4f19b01c46..cccf0ada4a 100644
--- a/crates/ra_ide_api/src/db.rs
+++ b/crates/ra_ide_api/src/db.rs
@@ -49,8 +49,9 @@ impl Default for RootDatabase {
         db.set_crate_graph(Default::default());
         db.set_local_roots(Default::default());
         db.set_library_roots(Default::default());
-        db.query_mut(ra_db::ParseQuery).set_lru_capacity(128);
-        db.query_mut(hir::db::ParseMacroQuery).set_lru_capacity(128);
+        let lru_cap = ra_db::DEFAULT_LRU_CAP;
+        db.query_mut(ra_db::ParseQuery).set_lru_capacity(lru_cap);
+        db.query_mut(hir::db::ParseMacroQuery).set_lru_capacity(lru_cap);
         db
     }
 }