diff --git a/packages/superdough/superdough.mjs b/packages/superdough/superdough.mjs
index 878e6c1e..ef62118e 100644
--- a/packages/superdough/superdough.mjs
+++ b/packages/superdough/superdough.mjs
@@ -316,9 +316,9 @@ export const superdough = async (value, deadline, hapDuration) => {
     coarse,
     crush,
     shape,
-    shapevol,
+    shapevol = 1,
     distort,
-    distortvol,
+    distortvol = 1,
     pan,
     vowel,
     delay = 0,