diff --git a/fpb.json b/fpb.json
index 9d6e9fd..fe77cad 100644
--- a/fpb.json
+++ b/fpb.json
@@ -13101,7 +13101,7 @@
                            "author": "Arya Popescu"
                         },
                         {
-                           "url": "https://fldit-www.cs.uni-dortmund.de/~peter/PS07/HR.pdf",
+                           "url": "https://fldit-www.cs.tu-dortmund.de/~peter/PS07/HR.pdf",
                            "title": "The Haskell Road to Logic, Math and Programming",
                            "author": "Kees Doets and Jan van Eijck",
                            "notes": [