diff --git a/pkgs/development/python-modules/tlsh/default.nix b/pkgs/development/python-modules/tlsh/default.nix
index 27c4ac2468ff..2a74a00539f9 100644
--- a/pkgs/development/python-modules/tlsh/default.nix
+++ b/pkgs/development/python-modules/tlsh/default.nix
@@ -20,10 +20,7 @@ buildPythonPackage {
   # no test data
   doCheck = false;
 
-  preConfigure = ''
-    mkdir build
-    cd build
-    cmake ..
+  postConfigure = ''
     cd ../py_ext
   '';