diff --git a/effect_modulated_delay.cpp b/effect_modulated_delay.cpp
index 9e74d5f..42fec14 100644
--- a/effect_modulated_delay.cpp
+++ b/effect_modulated_delay.cpp
@@ -102,7 +102,7 @@ void AudioEffectModulatedDelay::update(void)
       // Generate a an array with the size of INTERPOLATION_WINDOW_SIZE of x/y values around mod_idx for interpolation
       uint8_t c = 0;
       int16_t c_mod_idx = _circ_idx - int(mod_idx + 0.5); // This is the pointer to the value in the circular buffer at the current modulation index
-      for (j = INTERPOLATION_WINDOW_SIZE / -2; j <= INTERPOLATION_WINDOW_SIZE / 2; j++)
+      for (j = ~(INTERPOLATION_WINDOW_SIZE >> 1) | 0x01; j <= INTERPOLATION_WINDOW_SIZE >> 1; j++) // only another way to say: from -INTERPOLATION_WINDOW_SIZE/2 to INTERPOLATION_WINDOW_SIZE/2
       {
         int16_t jc_mod_idx = (c_mod_idx + j) % _delay_length; // The modulation index pointer plus the value of the current window pointer
         if (jc_mod_idx < 0)
@@ -120,15 +120,15 @@ void AudioEffectModulatedDelay::update(void)
         *bp = _delayline[_delay_length + c_mod_idx];
       else
         *bp = _delayline[c_mod_idx];
-/*      Serial.print("mod_idx=");
-      Serial.print(mod_idx, 3);
-      Serial.print(" c_mod_idx=");
-      Serial.print(c_mod_idx, DEC);
-      Serial.print(" MODULATION=");
-      Serial.print(*mp, DEC);
-      Serial.print(" DATA=");
-      Serial.print(*bp, DEC);
-      Serial.println();*/
+      /*      Serial.print("mod_idx=");
+            Serial.print(mod_idx, 3);
+            Serial.print(" c_mod_idx=");
+            Serial.print(c_mod_idx, DEC);
+            Serial.print(" MODULATION=");
+            Serial.print(*mp, DEC);
+            Serial.print(" DATA=");
+            Serial.print(*bp, DEC);
+            Serial.println();*/
 #endif
 
       bp++; // next audio data