diff --git a/src/apu.rs b/src/apu.rs
index c13153a58cdea4470f47adc305f18ff9c975bd67..bd81e6d1678ddcfb308a4b2aafba26d1282169e4 100644
--- a/src/apu.rs
+++ b/src/apu.rs
@@ -465,6 +465,7 @@ impl Apu {
         }
     }
 
+    #[inline(always)]
     pub fn output(&self) -> u8 {
         self.ch1_output() + self.ch2_output() + self.ch3_output() + self.ch4_output()
     }