diff --git a/src/lib.rs b/src/lib.rs
index bbb3153..9cdf1cf 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -246,6 +246,8 @@ pub struct Server<A> {
     rate_limits: RoutingNode<RateLimiter<IpAddr>>,
     #[cfg(feature="user_management")]
     data_dir: PathBuf,
+    #[cfg(feature="user_management")]
+    database: Option<sled::Db>,
     #[cfg(feature="certgen")]
     certgen_mode: CertGenMode,
 }
@@ -263,6 +265,8 @@ impl<A: ToSocketAddrs> Server<A> {
             rate_limits: RoutingNode::default(),
             #[cfg(feature="user_management")]
             data_dir: "data".into(),
+            #[cfg(feature="user_management")]
+            database: None,
             #[cfg(feature="certgen")]
             certgen_mode: CertGenMode::Interactive,
         }
@@ -271,12 +275,30 @@ impl<A: ToSocketAddrs> Server<A> {
     #[cfg(feature="user_management")]
     /// Sets the directory to store user data in
     ///
+    /// This will only be used if a database is not provided with [`set_database()`].
+    ///
     /// Defaults to `./data` if not specified
+    ///
+    /// [`set_database()`]: Self::set_database()
     pub fn set_database_dir(mut self, path: impl Into<PathBuf>) -> Self {
         self.data_dir = path.into();
         self
     }
 
+    #[cfg(feature="user_management")]
+    /// Sets a specific database to use
+    ///
+    /// This opens to trees within the database, both namespaced to avoid collisions.
+    ///
+    /// If this is not provided, a database will be opened at the directory provided by
+    /// [`set_database_dir()`]
+    ///
+    /// [`set_database_dir()`]: Self::set_database_dir()
+    pub fn set_database(mut self, db: sled::Db) -> Self {
+        self.database = Some(db);
+        self
+    }
+
     #[cfg(feature="certgen")]
     /// Determine where certificate config comes from, if generation is required
     ///
@@ -429,6 +451,9 @@ impl<A: ToSocketAddrs> Server<A> {
 
         self.routes.shrink();
 
+        #[cfg(feature="user_management")]
+        let data_dir = self.data_dir;
+
         let server = ServerInner {
             tls_acceptor: TlsAcceptor::from(config),
             routes: Arc::new(self.routes),
@@ -437,7 +462,9 @@ impl<A: ToSocketAddrs> Server<A> {
             #[cfg(feature="ratelimiting")]
             rate_limits: Arc::new(self.rate_limits),
             #[cfg(feature="user_management")]
-            manager: UserManager::new(self.data_dir)?,
+            manager: UserManager::new(
+                self.database.unwrap_or_else(move|| sled::open(data_dir).unwrap())
+            )?,
         };
 
         server.serve(listener).await
diff --git a/src/user_management/manager.rs b/src/user_management/manager.rs
index 61035d9..4dd639a 100644
--- a/src/user_management/manager.rs
+++ b/src/user_management/manager.rs
@@ -1,8 +1,6 @@
 use rustls::Certificate;
 use serde::{Deserialize, Serialize, de::DeserializeOwned};
 
-use std::path::Path;
-
 use crate::user_management::{User, Result};
 use crate::user_management::user::{RegisteredUser, NotSignedInUser, PartialUser};
 
@@ -37,8 +35,7 @@ impl UserManager {
     ///
     /// The `dir` argument is the path to a data directory, to be populated using sled.
     /// This will be created if it does not exist.
-    pub fn new(dir: impl AsRef<Path>) -> Result<Self> {
-       let db = sled::open(dir)?;
+    pub fn new(db: sled::Db) -> Result<Self> {
        Ok(Self {
            users: db.open_tree("gay.emii.kochab.users")?,
            certificates: db.open_tree("gay.emii.kochab.certificates")?,