diff --git a/database/src/fs.rs b/database/src/fs.rs
index f45aaf0..f34530c 100644
--- a/database/src/fs.rs
+++ b/database/src/fs.rs
@@ -478,7 +478,6 @@ impl Database for Filesystem {
     /// Note that this operation may take a long time, and is
     /// generally only useful for testing.
     fn check_consistency(&self) -> Result<()> {
-        use std::collections::HashMap;
         use failure::format_err;
 
         // A cache of all TPKs, for quick lookups.
diff --git a/database/src/lib.rs b/database/src/lib.rs
index 1a2acfe..9666302 100644
--- a/database/src/lib.rs
+++ b/database/src/lib.rs
@@ -1,6 +1,5 @@
 #![feature(proc_macro_hygiene, plugin, decl_macro)]
 #![recursion_limit = "1024"]
-#![feature(try_from)]
 
 use std::convert::TryFrom;
 use std::path::PathBuf;