diff --git a/flake.nix b/flake.nix
index 58fc1ae..ed2b09e 100644
--- a/flake.nix
+++ b/flake.nix
@@ -29,18 +29,11 @@
             in
               versionNum >= 3.11;
 
-          # Define package overrides for specific Python versions
-          packageOverrides = self: super: {
-            # Remove sphinx for Python versions under 3.11
-            sphinx = null;
-
-            # Add more package overrides as needed
-          };
-
-          # Create Python with package overrides
-          pythonWithOverrides = python.override {
-            packageOverrides = packageOverrides;
-          };
+          # Custom function to filter out sphinx when Python version is < 3.11
+          filterSphinxForOldPython = packages:
+            if isPython311OrHigher
+            then packages
+            else builtins.filter (p: p.pname or "" != "sphinx") packages;
 
           # Base Python packages that are always included
           basePackages = ps: with ps; [
@@ -52,23 +45,30 @@
             # Development tools
             black
             pytest
-            #ipython
+            ipython
+
+            # Include sphinx (will be filtered out later if needed)
+            sphinx
 
             # Add more default packages as needed
           ];
 
-          # Combine base packages with extra packages
-          allPackages = ps: (basePackages ps) ++ (extraPackages ps);
+          # Combine base packages with extra packages and filter if needed
+          allPackages = ps: 
+            let
+              combinedPackages = (basePackages ps) ++ (extraPackages ps);
+            in
+              filterSphinxForOldPython combinedPackages;
 
-          # Create the Python environment using the Python with overrides
-          pythonEnv = pythonWithOverrides.withPackages allPackages;
+          # Create the Python environment with filtered packages
+          pythonEnv = python.withPackages allPackages;
         in
           {
             # The Python environment
             package = pythonEnv;
 
             # Make the chosen Python version accessible
-            python = pythonWithOverrides;
+            python = python;
             inherit pythonVersion;
 
             # Development shell with the Python environment
@@ -78,7 +78,7 @@
               ] ++ extraSystemPackages;
 
               shellHook = ''
-                echo "Python $(${pythonWithOverrides}/bin/python --version)"
+                echo "Python $(${python}/bin/python --version)"
                 echo "Custom Python environment activated!"
               '';
             };
@@ -112,7 +112,7 @@
 
               pythonVersion = mkOption {
                 type = types.str;
-                default = "python311";
+                default = "python313";
                 description = "Python version to use (e.g., python39, python310, python311)";
               };