diff --git a/packages/superdough/helpers.mjs b/packages/superdough/helpers.mjs
index eb05c4cb..c97c06dc 100644
--- a/packages/superdough/helpers.mjs
+++ b/packages/superdough/helpers.mjs
@@ -40,6 +40,8 @@ export const getEnvelope = (attack, decay, sustain, release, velocity, begin) =>
 };
 
 export const getExpEnvelope = (attack, decay, sustain, release, velocity, begin) => {
+  sustain = Math.max(0.001, sustain);
+  velocity = Math.max(0.001, velocity);
   const gainNode = getAudioContext().createGain();
   gainNode.gain.setValueAtTime(0.0001, begin);
   gainNode.gain.exponentialRampToValueAtTime(velocity, begin + attack);