diff --git a/src/bin/fill-in-user-id.rs b/src/bin/fill-in-user-id.rs
index 2f78983cd7d..6a97fcd454a 100644
--- a/src/bin/fill-in-user-id.rs
+++ b/src/bin/fill-in-user-id.rs
@@ -52,16 +52,15 @@ struct GithubUser {
 }
 
 fn update(app: &App, tx: &postgres::transaction::Transaction) {
-    let mut rows = Vec::new();
-    let query = "SELECT id, gh_login, gh_access_token, gh_avatar FROM users \
-                  WHERE gh_id IS NULL";
-    for row in &tx.query(query, &[]).unwrap() {
+    let query = "SELECT id, gh_login, gh_access_token, gh_avatar FROM users
+                 WHERE gh_id IS NULL";
+    let rows = tx.query(query, &[]).unwrap().into_iter().map(|row| {
         let id: i32 = row.get("id");
         let login: String = row.get("gh_login");
         let token: String = row.get("gh_access_token");
         let avatar: Option<String> = row.get("gh_avatar");
-        rows.push((id, login, http::token(token), avatar));
-    }
+        (id, login, http::token(token), avatar)
+    }).collect::<Vec<_>>();
 
     for (id, login, token, avatar) in rows {
         println!("attempt: {}/{}", id, login);
diff --git a/src/krate.rs b/src/krate.rs
index 2f02a398ac2..191ee69c3df 100644
--- a/src/krate.rs
+++ b/src/krate.rs
@@ -1015,11 +1015,9 @@ pub fn downloads(req: &mut Request) -> CargoResult<Response> {
                                  WHERE date > $1
                                    AND version_id = ANY($2)
                                  ORDER BY date ASC")?;
-    let mut downloads = Vec::new();
-    for row in stmt.query(&[&cutoff_date, &ids])?.iter() {
-        let download: VersionDownload = Model::from_row(&row);
-        downloads.push(download.encodable());
-    }
+    let downloads = stmt.query(&[&cutoff_date, &ids])?.iter().map(|row| {
+        VersionDownload::from_row(&row).encodable()
+    }).collect::<Vec<_>>();
 
     let stmt = tx.prepare("\
           SELECT COALESCE(to_char(DATE(version_downloads.date), 'YYYY-MM-DD'), '') AS date,
@@ -1032,13 +1030,12 @@ pub fn downloads(req: &mut Request) -> CargoResult<Response> {
              AND versions.id != ALL($3)
         GROUP BY DATE(version_downloads.date)
         ORDER BY DATE(version_downloads.date) ASC")?;
-    let mut extra = Vec::new();
-    for row in stmt.query(&[&cutoff_date, &krate.id, &ids])?.iter() {
-        extra.push(ExtraDownload {
+    let extra = stmt.query(&[&cutoff_date, &krate.id, &ids])?.iter().map(|row| {
+        ExtraDownload {
             downloads: row.get("downloads"),
             date: row.get("date")
-        });
-    }
+        }
+    }).collect::<Vec<_>>();
 
     #[derive(RustcEncodable)]
     struct ExtraDownload { date: String, downloads: i64 }
diff --git a/src/version.rs b/src/version.rs
index a22eab42c6a..6815074db85 100644
--- a/src/version.rs
+++ b/src/version.rs
@@ -307,11 +307,9 @@ pub fn downloads(req: &mut Request) -> CargoResult<Response> {
     let stmt = tx.prepare("SELECT * FROM version_downloads
                                 WHERE date > $1 AND version_id = $2
                                 ORDER BY date ASC")?;
-    let mut downloads = Vec::new();
-    for row in stmt.query(&[&cutoff_date, &version.id])?.iter() {
-        let download: VersionDownload = Model::from_row(&row);
-        downloads.push(download.encodable());
-    }
+    let downloads = stmt.query(&[&cutoff_date, &version.id])?.iter().map(|row| {
+        VersionDownload::from_row(&row).encodable()
+    }).collect();
 
     #[derive(RustcEncodable)]
     struct R { version_downloads: Vec<EncodableVersionDownload> }