diff --git a/src/client/graphics/SpriteLoader.ts b/src/client/graphics/SpriteLoader.ts
index 873affd3a..49abd3c1e 100644
--- a/src/client/graphics/SpriteLoader.ts
+++ b/src/client/graphics/SpriteLoader.ts
@@ -90,6 +90,9 @@ export const getColoredSprite = (
   }
 
   const sprite = getSpriteForUnit(unit.type());
+  if (sprite === null) {
+    throw new Error(`Failed to load sprite for ${unit.type()}`);
+  }
 
   const territoryRgb = territoryColor.toRgb();
   const borderRgb = borderColor.toRgb();