diff --git a/pkgs/development/python-modules/testfixtures/default.nix b/pkgs/development/python-modules/testfixtures/default.nix
index c330b5e18b89..be217a16b07a 100644
--- a/pkgs/development/python-modules/testfixtures/default.nix
+++ b/pkgs/development/python-modules/testfixtures/default.nix
@@ -12,11 +12,11 @@
 
 buildPythonPackage rec {
   pname = "testfixtures";
-  version = "6.18.1";
+  version = "6.18.3";
 
   src = fetchPypi {
     inherit pname version;
-    sha256 = "sha256-CmQic39tibRc3vHi31V29SrQ9QeVYALOECDaqfRCEdY=";
+    sha256 = "sha256-JgAQCulv/QgjNLN441VVD++LSlKab6TDT0cTCQXHQm0=";
   };
 
   checkInputs = [