diff --git a/MicroMDAEPiano.ino b/MicroMDAEPiano.ino
index d224406..15f12aa 100644
--- a/MicroMDAEPiano.ino
+++ b/MicroMDAEPiano.ino
@@ -264,7 +264,6 @@ void loop()
 {
   int16_t* audio_buffer_r; // pointer to AUDIO_BLOCK_SAMPLES * sizeof(int16_t)
   int16_t* audio_buffer_l; // pointer to AUDIO_BLOCK_SAMPLES * sizeof(int16_t)
-  const uint16_t audio_block_time_ms = 1000000 / (SAMPLE_RATE / AUDIO_BLOCK_SAMPLES);
 
   // Main sound calculation
   if (queue_r.available() && queue_l.available() && fill_audio_buffer > audio_block_time_us - 10)
@@ -293,7 +292,7 @@ void loop()
     elapsedMicros t1;
     ep->process(audio_buffer_l, audio_buffer_r);
     uint32_t t2 = t1;
-    if (t2 > audio_block_time_ms) // everything greater 2.9ms is a buffer underrun!
+    if (t2 > audio_block_time_us) // everything greater 2.9ms is a buffer underrun!
       xrun++;
     if (t2 > render_time_max)
       render_time_max = t2;