diff --git a/examples/python/flake.nix b/examples/python/flake.nix
index 2f8d132d..9f8b9abc 100644
--- a/examples/python/flake.nix
+++ b/examples/python/flake.nix
@@ -16,6 +16,6 @@
       source = src;
     })
     // {
-      checks.x86_64-linux.aiohttp = self.packages.x86_64-linux.aiohttp;
+      checks.x86_64-linux.aiohttp = self.packages.x86_64-linux.main;
     };
 }
diff --git a/src/subsystems/python/builders/simple-builder/default.nix b/src/subsystems/python/builders/simple-builder/default.nix
index 7d1a2bbd..096893ac 100644
--- a/src/subsystems/python/builders/simple-builder/default.nix
+++ b/src/subsystems/python/builders/simple-builder/default.nix
@@ -12,6 +12,7 @@
     getSource,
     packageVersions,
     subsystemAttrs,
+    produceDerivation,
     ...
   }: let
     l = lib // builtins;
@@ -22,14 +23,6 @@
       then python.pkgs.buildPythonApplication
       else python.pkgs.buildPythonPackage;
 
-    packageName =
-      if defaultPackageName == null
-      then
-        if subsystemAttrs.application
-        then "application"
-        else "environment"
-      else defaultPackageName;
-
     allDependencySources' =
       l.flatten
       (l.mapAttrsToList
@@ -44,8 +37,8 @@
       (src: src.original or src)
       allDependencySources';
 
-    package = buildFunc {
-      name = packageName;
+    package = produceDerivation defaultPackageName (buildFunc {
+      name = defaultPackageName;
       src = getSource defaultPackageName defaultPackageVersion;
       format = "setuptools";
       buildInputs = pkgs.pythonManylinuxPackages.manylinux1;
@@ -73,7 +66,7 @@
           --no-cache \
           $pipInstallFlags
       '';
-    };
+    });
   in {
     packages.${defaultPackageName}.${defaultPackageVersion} = package;
   };
diff --git a/src/utils/override.nix b/src/utils/override.nix
index d8df9be8..1a2888a7 100644
--- a/src/utils/override.nix
+++ b/src/utils/override.nix
@@ -131,14 +131,19 @@
       overrideFuncs =
         lib.mapAttrsToList
         (funcName: func: {inherit funcName func;})
-        (lib.filterAttrs (n: v: lib.hasPrefix "override" n) condOverride);
+        (lib.filterAttrs (
+            n: v:
+              lib.hasPrefix "override" n
+              && (! b.elem n ["overrideDerivation" "overridePythonAttrs"])
+          )
+          condOverride);
 
       singleArgOverrideFuncs = let
         availableFunctions =
           lib.mapAttrs
           (funcName: func: getOverrideFunctionArgs func)
           (lib.filterAttrs
-            (funcName: func: lib.hasPrefix "override" funcName)
+            (funcName: func: lib.hasPrefix "override" funcName && funcName != "overrideDerivation" && funcName != "overridePythonAttrs")
             base_derivation);
 
         getOverrideFuncNameForAttrName = attrName: let