diff --git a/pkgs/by-name/ca/casadi/package.nix b/pkgs/by-name/ca/casadi/package.nix
index 0f1f3e3d7a00..5cd35b064342 100644
--- a/pkgs/by-name/ca/casadi/package.nix
+++ b/pkgs/by-name/ca/casadi/package.nix
@@ -10,7 +10,6 @@
   cplex,
   fatrop,
   fetchFromGitHub,
-  fetchpatch,
   gurobi,
   highs,
   hpipm,
@@ -37,40 +36,27 @@
 
 stdenv.mkDerivation (finalAttrs: {
   pname = "casadi";
-  version = "3.6.6";
+  version = "3.6.7";
 
   src = fetchFromGitHub {
     owner = "casadi";
     repo = "casadi";
     rev = finalAttrs.version;
-    hash = "sha256-T4aaBS918NbUEwWkSx0URi0W9uhCB8IFmzRcOR7T8Og=";
+    hash = "sha256-Mft0qhjdAbU82RgjYuKue5p7EqbTbt3ii5yXSsCFHrQ=";
   };
 
-  patches = [
-    (fetchpatch {
-      name = "add-FindSPRAL.cmake.patch";
-      url = "https://github.com/casadi/casadi/pull/3792/commits/28bc1b03e67ae06dea0c8557057020f5651be7ad.patch";
-      hash = "sha256-t0+RnXoFakmoX93MhN08RWAbCg6Nerh42LicBBgAkRQ=";
-    })
-  ];
-
   postPatch =
     ''
-      # fix case of fatropConfig.cmake & hpipmConfig.cmake
+      # fix case of hpipmConfig.cmake
       substituteInPlace CMakeLists.txt --replace-fail \
         "FATROP HPIPM" \
-        "fatrop hpipm"
+        "FATROP hpipm"
 
       # nix provide lib/clang headers in libclang, not in llvm.
       substituteInPlace casadi/interfaces/clang/CMakeLists.txt --replace-fail \
         '$'{CLANG_LLVM_LIB_DIR} \
         ${llvmPackages_17.libclang.lib}/lib
 
-      # fix fatrop includes
-      substituteInPlace casadi/interfaces/fatrop/fatrop_conic_interface.hpp --replace-fail \
-        "<ocp/" \
-        "<fatrop/ocp/"
-
       # fix mumps lib name. No idea where this comes from.
       substituteInPlace cmake/FindMUMPS.cmake --replace-fail \
         "mumps_seq" \
@@ -173,7 +159,7 @@ stdenv.mkDerivation (finalAttrs: {
     (lib.cmakeBool "WITH_CSPARSE" true)
     (lib.cmakeBool "WITH_BLASFEO" true)
     (lib.cmakeBool "WITH_HPIPM" true)
-    (lib.cmakeBool "WITH_FATROP" false) # invalid new-expression of abstract class type 'casadi::CasadiStructuredQP'
+    (lib.cmakeBool "WITH_FATROP" true)
     (lib.cmakeBool "WITH_BUILD_FATROP" false)
     (lib.cmakeBool "WITH_SUPERSCS" false) # packaging too chaotic
     (lib.cmakeBool "WITH_BUILD_OSQP" false)
diff --git a/pkgs/by-name/fa/fatrop/package.nix b/pkgs/by-name/fa/fatrop/package.nix
index 87d66c67802a..f575b763d04a 100644
--- a/pkgs/by-name/fa/fatrop/package.nix
+++ b/pkgs/by-name/fa/fatrop/package.nix
@@ -11,26 +11,15 @@
 
 stdenv.mkDerivation (finalAttrs: {
   pname = "fatrop";
-  version = "0.0.1";
+  version = "0.0.4";
 
   src = fetchFromGitHub {
     owner = "meco-group";
     repo = "fatrop";
     rev = "v${finalAttrs.version}";
-    hash = "sha256-c4qYh8RutRsMIx3m0oxXy73fnLTBGVZ1QjFcLEJ413Y=";
+    hash = "sha256-XVOS9L2vQeFkPXZieX1ZJiVagR0f2BtiRmSDPB9LQeI=";
   };
 
-  postPatch = lib.optionalString pythonSupport ''
-    # avoid submodule
-    rmdir external/pybind11
-    ln -s ${python3Packages.pybind11.src} external/pybind11
-
-    # install python module
-    echo ""  >> fatropy/CMakeLists.txt
-    echo "install(DIRECTORY fatropy DESTINATION ${python3Packages.python.sitePackages})" >> fatropy/CMakeLists.txt
-    echo "install(TARGETS _fatropy DESTINATION ${python3Packages.python.sitePackages}/fatropy)" >> fatropy/CMakeLists.txt
-  '';
-
   nativeBuildInputs = [ cmake ];
   buildInputs =
     [ blasfeo ]