diff --git a/src/js/mods/mod_interface.js b/src/js/mods/mod_interface.js
index a63cc9a8..e2bb15b4 100644
--- a/src/js/mods/mod_interface.js
+++ b/src/js/mods/mod_interface.js
@@ -78,7 +78,6 @@ export class ModInterface {
     }
 
     registerSprite(spriteId, base64string) {
-        assert(base64string.startsWith("data:image"));
         const img = new Image();
 
         const sprite = new AtlasSprite(spriteId);