diff --git a/crates/ra_arena/src/lib.rs b/crates/ra_arena/src/lib.rs
index 3b7cb77b181..3ec8d3b60b6 100644
--- a/crates/ra_arena/src/lib.rs
+++ b/crates/ra_arena/src/lib.rs
@@ -79,7 +79,7 @@ impl<ID: ArenaId, T> Arena<ID, T> {
         self.data.push(value);
         ID::from_raw(id)
     }
-    pub fn iter(&self) -> impl Iterator<Item = (ID, &T)> {
+    pub fn iter(&self) -> impl Iterator<Item = (ID, &T)> + ExactSizeIterator {
         self.data.iter().enumerate().map(|(idx, value)| (ID::from_raw(RawId(idx as u32)), value))
     }
 }
diff --git a/crates/ra_lsp_server/src/main_loop.rs b/crates/ra_lsp_server/src/main_loop.rs
index 8e830c8b858..9a38d43d2ae 100644
--- a/crates/ra_lsp_server/src/main_loop.rs
+++ b/crates/ra_lsp_server/src/main_loop.rs
@@ -269,7 +269,7 @@ fn main_loop_inner(
             && pending_libraries.is_empty()
             && in_flight_libraries == 0
         {
-            let n_packages: usize = state.workspaces.iter().map(|it| it.count()).sum();
+            let n_packages: usize = state.workspaces.iter().map(|it| it.n_packages()).sum();
             if state.options.show_workspace_loaded {
                 let msg = format!("workspace loaded, {} rust packages", n_packages);
                 show_message(req::MessageType::Info, msg, msg_sender);
diff --git a/crates/ra_lsp_server/src/world.rs b/crates/ra_lsp_server/src/world.rs
index 1d775591046..b57cdf925a7 100644
--- a/crates/ra_lsp_server/src/world.rs
+++ b/crates/ra_lsp_server/src/world.rs
@@ -211,7 +211,7 @@ impl WorldSnapshot {
         } else {
             res.push_str("workspaces:\n");
             for w in self.workspaces.iter() {
-                res += &format!("{} packages loaded\n", w.count());
+                res += &format!("{} packages loaded\n", w.n_packages());
             }
         }
         res.push_str("\nanalysis:\n");
diff --git a/crates/ra_project_model/src/cargo_workspace.rs b/crates/ra_project_model/src/cargo_workspace.rs
index 2b06e9e372c..712d8818f8a 100644
--- a/crates/ra_project_model/src/cargo_workspace.rs
+++ b/crates/ra_project_model/src/cargo_workspace.rs
@@ -167,7 +167,7 @@ impl CargoWorkspace {
         Ok(CargoWorkspace { packages, targets, workspace_root: meta.workspace_root })
     }
 
-    pub fn packages<'a>(&'a self) -> impl Iterator<Item = Package> + 'a {
+    pub fn packages<'a>(&'a self) -> impl Iterator<Item = Package> + ExactSizeIterator + 'a {
         self.packages.iter().map(|(id, _pkg)| id)
     }
 
diff --git a/crates/ra_project_model/src/lib.rs b/crates/ra_project_model/src/lib.rs
index 647a1f36585..8e81396d445 100644
--- a/crates/ra_project_model/src/lib.rs
+++ b/crates/ra_project_model/src/lib.rs
@@ -112,8 +112,7 @@ impl ProjectWorkspace {
                 roots
             }
             ProjectWorkspace::Cargo { cargo, sysroot } => {
-                let mut roots =
-                    Vec::with_capacity(cargo.packages().count() + sysroot.crates().count());
+                let mut roots = Vec::with_capacity(cargo.packages().len() + sysroot.crates().len());
                 for pkg in cargo.packages() {
                     let root = pkg.root(&cargo).to_path_buf();
                     let member = pkg.is_member(&cargo);
@@ -127,10 +126,12 @@ impl ProjectWorkspace {
         }
     }
 
-    pub fn count(&self) -> usize {
+    pub fn n_packages(&self) -> usize {
         match self {
             ProjectWorkspace::Json { project } => project.crates.len(),
-            ProjectWorkspace::Cargo { cargo, .. } => cargo.packages().count(),
+            ProjectWorkspace::Cargo { cargo, sysroot } => {
+                cargo.packages().len() + sysroot.crates().len()
+            }
         }
     }
 
diff --git a/crates/ra_project_model/src/sysroot.rs b/crates/ra_project_model/src/sysroot.rs
index 4f6e880dd47..3f34d51ccb9 100644
--- a/crates/ra_project_model/src/sysroot.rs
+++ b/crates/ra_project_model/src/sysroot.rs
@@ -28,7 +28,7 @@ impl Sysroot {
         self.by_name("std")
     }
 
-    pub fn crates<'a>(&'a self) -> impl Iterator<Item = SysrootCrate> + 'a {
+    pub fn crates<'a>(&'a self) -> impl Iterator<Item = SysrootCrate> + ExactSizeIterator + 'a {
         self.crates.iter().map(|(id, _data)| id)
     }