diff --git a/lib/custom-element/api/graphics-api.js b/lib/custom-element/api/graphics-api.js
index fff201a1..d065782c 100644
--- a/lib/custom-element/api/graphics-api.js
+++ b/lib/custom-element/api/graphics-api.js
@@ -125,7 +125,7 @@ class GraphicsAPI extends BaseAPI {
    * transforms: scale
    */
   scale(x, y) {
-    y = y ?? x;
+    y = y ? y : x; // NOTE: this turns y=0 into y=x, which is fine. Scaling by 0 is really silly =)
     this.ctx.scale(x, y);
   }
   /**
diff --git a/lib/custom-element/api/types/vector.js b/lib/custom-element/api/types/vector.js
index c67832ca..8a9639a1 100644
--- a/lib/custom-element/api/types/vector.js
+++ b/lib/custom-element/api/types/vector.js
@@ -16,8 +16,8 @@ class Vector {
     let sum = 0;
     sum += (this.x - other.x) ** 2;
     sum += (this.y - other.y) ** 2;
-    let z1 = this.z ?? 0;
-    let z2 = other.z ?? 0;
+    let z1 = this.z ? this.z : 0;
+    let z2 = other.z ? other.z : 0;
     sum += (z1 - z2) ** 2;
     return sum ** 0.5;
   }
diff --git a/tools/locale-strings.js b/tools/locale-strings.js
index 67d5f687..c9e926b8 100644
--- a/tools/locale-strings.js
+++ b/tools/locale-strings.js
@@ -54,7 +54,7 @@ class LocaleStrings {
     Object.keys(localeStringData).forEach((id) => {
       const map = localeStringData[id];
       if (typeof map !== "object") return;
-      const value = map[locale] ?? map[defaultLocale];
+      const value = map[locale] ? map[locale] :  map[defaultLocale];
       if (!value) throw new Error(`unknown locale string id "${id}".`);
       strings[id] = value;