diff --git a/pkgs/tools/networking/ipv6calc/default.nix b/pkgs/tools/networking/ipv6calc/default.nix
index aea77f725120..b28ea0dbbe52 100644
--- a/pkgs/tools/networking/ipv6calc/default.nix
+++ b/pkgs/tools/networking/ipv6calc/default.nix
@@ -4,11 +4,11 @@
 
 stdenv.mkDerivation rec {
   name = "ipv6calc-${version}";
-  version = "0.99.2";
+  version = "1.0.0";
 
   src = fetchurl {
     url = "ftp://ftp.deepspace6.net/pub/ds6/sources/ipv6calc/${name}.tar.gz";
-    sha256 = "1vs64v8v5g9rskg46baqrzyay86vs7ln3i5r5ippa9l6ildyrvpj";
+    sha256 = "1gcl8mqjdn5j1rcnv2gz2j0i8ayx747hwzjyiazl6j43c5g4bc3l";
   };
 
   buildInputs = [ geoip geolite-legacy getopt ip2location-c openssl ];