diff --git a/lib/extract/extractColor.js b/lib/extract/extractColor.js
index aad36b80..f2539279 100644
--- a/lib/extract/extractColor.js
+++ b/lib/extract/extractColor.js
@@ -423,7 +423,7 @@ export default function extractColor(color) {
   const b = parsedColor[2];
   const a = parsedColor[3];
 
-  let int32Color =
+  const int32Color =
     ((a === undefined ? 0xff000000 : Math.round(a * 255) << 24) |
       (Math.round(r * 255) << 16) |
       (Math.round(g * 255) << 8) |