diff --git a/agb/src/rng.rs b/agb/src/rng.rs
index f0ef404f..b98ad6ce 100644
--- a/agb/src/rng.rs
+++ b/agb/src/rng.rs
@@ -52,6 +52,12 @@ impl RandomNumberGenerator {
     }
 }
 
+impl Default for RandomNumberGenerator {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 static GLOBAL_RNG: Mutex<RefCell<RandomNumberGenerator>> =
     Mutex::new(RefCell::new(RandomNumberGenerator::new()));
 
diff --git a/agb/src/sync/locks.rs b/agb/src/sync/locks.rs
index fdb7033f..18155522 100644
--- a/agb/src/sync/locks.rs
+++ b/agb/src/sync/locks.rs
@@ -60,6 +60,12 @@ impl RawMutex {
 unsafe impl Send for RawMutex {}
 unsafe impl Sync for RawMutex {}
 
+impl Default for RawMutex {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 /// A guard representing an active lock on an [`RawMutex`].
 pub struct RawMutexGuard<'a>(&'a RawMutex);
 impl<'a> Drop for RawMutexGuard<'a> {