diff --git a/pkgs/development/python-modules/tskit/default.nix b/pkgs/development/python-modules/tskit/default.nix
index bb5139b425b0..522d4a57adbc 100644
--- a/pkgs/development/python-modules/tskit/default.nix
+++ b/pkgs/development/python-modules/tskit/default.nix
@@ -10,13 +10,13 @@
 
 buildPythonPackage rec {
   pname = "tskit";
-  version = "0.5.5";
+  version = "0.5.6";
   format = "pyproject";
   disabled = pythonOlder "3.7";
 
   src = fetchPypi {
     inherit pname version;
-    hash = "sha256-phhBTAHAPlBnmzSiLmPYDMg1Mui85NZacni3WuYAc6c=";
+    hash = "sha256-3f4hPxywY822mCF3IwooBezX38fM1zAm4Th4q//SzkY=";
   };
 
   nativeBuildInputs = [