diff --git a/ipynb/How To Count Things.ipynb b/ipynb/How To Count Things.ipynb
index a5b715e..d2fe304 100644
--- a/ipynb/How To Count Things.ipynb	
+++ b/ipynb/How To Count Things.ipynb	
@@ -79,7 +79,7 @@
     "\n",
     "> A typical barcode is pictured below. A valid barcode consists of alternating black and white stripes, where each stripe is either 1, 2, or 3 units wide. For a box that is *n* units wide, how many different valid barcodes are there?\n",
     "\n",
-    "![barcode](https://help.shopify.com/assets/manual/sell-in-person/hardware/barcode-scanner/1d-barcode-4fbf513f48675746ba39d9ea5078f377e5e1bb9de2966336088af8394b893b78.png)\n",
+    "![barcode](https://upload.wikimedia.org/wikipedia/commons/thumb/a/a2/EAN-13-5901234123457.svg/250px-EAN-13-5901234123457.svg.png)\n",
     "\n",
     "We'll represent a unit as a character, `'B'` or `'W'`, and a barcode as a string of *n* units. The barcode above would start with `'BWWBW...'`.  A valid string is one without 4 of the same character/unit in a row; `valid_barcode` tests for this.\n",
     "\n",