diff --git a/tracker/agb-tracker-interop/src/lib.rs b/tracker/agb-tracker-interop/src/lib.rs
index a1a094b7..cd015246 100644
--- a/tracker/agb-tracker-interop/src/lib.rs
+++ b/tracker/agb-tracker-interop/src/lib.rs
@@ -29,8 +29,8 @@ pub struct Pattern {
 
 #[derive(Debug)]
 pub struct PatternSlot {
-    pub speed: Num<u32, 8>,
-    pub sample: usize,
+    pub speed: Num<u16, 8>,
+    pub sample: u16,
     pub effect1: PatternEffect,
     pub effect2: PatternEffect,
 }
diff --git a/tracker/agb-tracker/src/lib.rs b/tracker/agb-tracker/src/lib.rs
index 69bd6b37..a96cd08c 100644
--- a/tracker/agb-tracker/src/lib.rs
+++ b/tracker/agb-tracker/src/lib.rs
@@ -80,12 +80,22 @@ impl Tracker {
 
         for (channel, pattern_slot) in self.channels.iter_mut().zip(pattern_slots) {
             if pattern_slot.sample != 0 && self.tick == 0 {
-                let sample = &self.track.samples[pattern_slot.sample - 1];
+                let sample = &self.track.samples[pattern_slot.sample as usize - 1];
                 channel.play_sound(mixer, sample);
             }
 
-            channel.apply_effect(mixer, &pattern_slot.effect1, self.tick, pattern_slot.speed);
-            channel.apply_effect(mixer, &pattern_slot.effect2, self.tick, pattern_slot.speed);
+            channel.apply_effect(
+                mixer,
+                &pattern_slot.effect1,
+                self.tick,
+                pattern_slot.speed.change_base(),
+            );
+            channel.apply_effect(
+                mixer,
+                &pattern_slot.effect2,
+                self.tick,
+                pattern_slot.speed.change_base(),
+            );
         }
 
         self.increment_step();
diff --git a/tracker/agb-xm-core/src/lib.rs b/tracker/agb-xm-core/src/lib.rs
index 3722861f..f02e9370 100644
--- a/tracker/agb-xm-core/src/lib.rs
+++ b/tracker/agb-xm-core/src/lib.rs
@@ -229,8 +229,8 @@ pub fn parse_module(module: &Module) -> TokenStream {
                     );
 
                     pattern_data.push(agb_tracker_interop::PatternSlot {
-                        speed,
-                        sample,
+                        speed: speed.try_change_base().unwrap(),
+                        sample: sample as u16,
                         effect1,
                         effect2,
                     });