diff --git a/src/lib/utils/interpolate.js b/src/lib/utils/interpolate.js
index ec1ebf1..2dbb744 100644
--- a/src/lib/utils/interpolate.js
+++ b/src/lib/utils/interpolate.js
@@ -11,7 +11,7 @@ export default (values) => {
 
   return values.reduce((stack, next, i) => {
     if (isFinite(next) || i === values.length - 1) {
-      next ??= stack.at(-1)
+      next = next ?? stack.at(-1)
 
       if (count > 0) {
         const prev = stack.at(-1) ?? next
diff --git a/src/templates/legend.js b/src/templates/legend.js
index 7cba522..32be175 100644
--- a/src/templates/legend.js
+++ b/src/templates/legend.js
@@ -78,7 +78,7 @@ export default ({
 } = {}) => {
   if (!data) return
 
-  includeDefs ??= includeWrap
+  includeDefs = includeDefs ?? includeWrap
 
   const keys = Object.values(
     data.flat().reduce((m, d) => {