diff --git a/src/processor/memory/mmio/apu/channels.rs b/src/processor/memory/mmio/apu/channels.rs
index 783d5aa..6c11093 100644
--- a/src/processor/memory/mmio/apu/channels.rs
+++ b/src/processor/memory/mmio/apu/channels.rs
@@ -210,9 +210,9 @@ impl PwmChannel {
     pub(super) fn update_sweep(&mut self, data: u8) {
         self.sweep.pace = (data & 0b1110000) >> 4;
         self.sweep.mode = if get_bit(data, 3) {
-            EnvelopeMode::Decrease
-        } else {
             EnvelopeMode::Increase
+        } else {
+            EnvelopeMode::Decrease
         };
         self.sweep.slope = data & 0b111;
     }
@@ -221,7 +221,7 @@ impl PwmChannel {
         set_or_clear_bit(
             (0b10000000 | (self.sweep.pace << 4) & 0b1110000) | (self.sweep.slope & 0b111),
             3,
-            self.sweep.mode == EnvelopeMode::Decrease,
+            self.sweep.mode == EnvelopeMode::Increase,
         )
     }
 
@@ -251,7 +251,7 @@ impl PwmChannel {
             (self.queued_envelope.rate & 0b111)
                 | ((self.queued_envelope.initial_volume & 0b1111) << 4),
             3,
-            self.queued_envelope.mode == EnvelopeMode::Decrease,
+            self.queued_envelope.mode == EnvelopeMode::Increase,
         )
     }