diff --git a/examples/services-agnostic/constructors/constructors.nix b/examples/services-agnostic/constructors/constructors.nix
index 202370a..f9f106f 100644
--- a/examples/services-agnostic/constructors/constructors.nix
+++ b/examples/services-agnostic/constructors/constructors.nix
@@ -28,13 +28,13 @@ in
 
   supervisord = import ./supervisord {
     inherit createManagedProcess runtimeDir logDir;
-    inherit (pkgs.pythonPackages) supervisor;
+    inherit (pkgs.python3Packages) supervisor;
   };
 
   extendableSupervisord = import ./supervisord/extendable.nix {
     inherit createManagedProcess libDir runtimeDir logDir;
     inherit (pkgs) writeTextFile;
-    inherit (pkgs.pythonPackages) supervisor;
+    inherit (pkgs.python3Packages) supervisor;
   };
 
   docker = import ./docker {
diff --git a/examples/webapps-agnostic/network-logical.nix b/examples/webapps-agnostic/network-logical.nix
index 416042e..2fdb5af 100644
--- a/examples/webapps-agnostic/network-logical.nix
+++ b/examples/webapps-agnostic/network-logical.nix
@@ -17,7 +17,7 @@ in
     services.disnix.enable = true;
     services.openssh.enable = true;
     networking.firewall.enable = false;
-    environment.systemPackages = [ pkgs.pythonPackages.supervisor nixproc-generate-config ];
+    environment.systemPackages = [ pkgs.python3Packages.supervisor nixproc-generate-config ];
   };
 
   test2 = {pkgs, ...}:
@@ -36,6 +36,6 @@ in
     services.disnix.enable = true;
     services.openssh.enable = true;
     networking.firewall.enable = false;
-    environment.systemPackages = [ pkgs.pythonPackages.supervisor nixproc-generate-config ];
+    environment.systemPackages = [ pkgs.python3Packages.supervisor nixproc-generate-config ];
   };
 }
diff --git a/nixproc/backends/supervisord/image-steps/supervisord.nix b/nixproc/backends/supervisord/image-steps/supervisord.nix
index f0252e9..1284aaf 100644
--- a/nixproc/backends/supervisord/image-steps/supervisord.nix
+++ b/nixproc/backends/supervisord/image-steps/supervisord.nix
@@ -1,8 +1,8 @@
 {pkgs, common, input, result}:
 
 result // {
-  contents = result.contents or [] ++ [ pkgs.pythonPackages.supervisor ];
+  contents = result.contents or [] ++ [ pkgs.python3Packages.supervisor ];
   config = result.config or {} // {
-    Cmd = [ "${pkgs.pythonPackages.supervisor}/bin/supervisord" "--nodaemon" "--configuration" "/etc/supervisor/supervisord.conf" "--logfile" "/var/log/supervisord.log" "--pidfile" "/var/run/supervisord.pid" ];
+    Cmd = [ "${pkgs.python3Packages.supervisor}/bin/supervisord" "--nodaemon" "--configuration" "/etc/supervisor/supervisord.conf" "--logfile" "/var/log/supervisord.log" "--pidfile" "/var/run/supervisord.pid" ];
   };
 }
diff --git a/nixproc/backends/supervisord/test-module/default.nix b/nixproc/backends/supervisord/test-module/default.nix
index 474d859..4a324c7 100644
--- a/nixproc/backends/supervisord/test-module/default.nix
+++ b/nixproc/backends/supervisord/test-module/default.nix
@@ -22,7 +22,7 @@ in
   systemPackages = [
     tools.sysvinit
     tools.supervisord
-    pkgs.pythonPackages.supervisor
+    pkgs.python3Packages.supervisor
   ];
 
   additionalPaths = [ processesEnvProcessManager processesEnvSystem ];
diff --git a/nixproc/create-managed-process/universal/create-managed-process-universal.nix b/nixproc/create-managed-process/universal/create-managed-process-universal.nix
index bb94eea..157176d 100644
--- a/nixproc/create-managed-process/universal/create-managed-process-universal.nix
+++ b/nixproc/create-managed-process/universal/create-managed-process-universal.nix
@@ -41,7 +41,7 @@ let
 
   createSupervisordProgram = import ../../backends/supervisord/create-supervisord-program.nix {
     inherit (pkgs) writeTextFile stdenv lib;
-    inherit (pkgs.pythonPackages) supervisor;
+    inherit (pkgs.python3Packages) supervisor;
     inherit createCredentials basePackages forceDisableUserChange runtimeDir;
   };
 
diff --git a/tests/services/supervisord/default.nix b/tests/services/supervisord/default.nix
index ff5891d..71ddbea 100644
--- a/tests/services/supervisord/default.nix
+++ b/tests/services/supervisord/default.nix
@@ -27,7 +27,7 @@ let
 in
 testService {
   exprFile = ./processes.nix;
-  systemPackages = [ pkgs.pythonPackages.supervisor ];
+  systemPackages = [ pkgs.python3Packages.supervisor ];
 
   readiness = {instanceName, instance, ...}:
     ''
diff --git a/tests/webapps-agnostic-supervisord-stateless.nix b/tests/webapps-agnostic-supervisord-stateless.nix
index 56848bb..ea7c56d 100644
--- a/tests/webapps-agnostic-supervisord-stateless.nix
+++ b/tests/webapps-agnostic-supervisord-stateless.nix
@@ -32,7 +32,7 @@ makeTest {
       environment.systemPackages = [
         pkgs.stdenv
         pkgs.daemon
-        pkgs.pythonPackages.supervisor
+        pkgs.python3Packages.supervisor
         pkgs.dysnomia
         tools.common
         tools.systemd
diff --git a/tests/webapps-agnostic-supervisord.nix b/tests/webapps-agnostic-supervisord.nix
index ab53ca3..226e1a5 100644
--- a/tests/webapps-agnostic-supervisord.nix
+++ b/tests/webapps-agnostic-supervisord.nix
@@ -73,7 +73,7 @@ makeTest {
 
       environment.systemPackages = [
         pkgs.stdenv
-        pkgs.pythonPackages.supervisor
+        pkgs.python3Packages.supervisor
         pkgs.dysnomia
         tools.common
         tools.systemd