diff --git a/nixos/modules/services/hardware/udev.nix b/nixos/modules/services/hardware/udev.nix
index 74ec335c750..74200eec4c0 100644
--- a/nixos/modules/services/hardware/udev.nix
+++ b/nixos/modules/services/hardware/udev.nix
@@ -116,7 +116,7 @@ let
           )"
           echo "$localFile ($remoteFile) contains references to $refs."
         done
-        ${optionalString (!cfg.allowImpurePaths) "exit 1"}
+        exit 1
       fi
 
       ${optionalString config.networking.usePredictableInterfaceNames ''
@@ -232,20 +232,6 @@ in
         '';
       };
 
-      allowImpurePaths = mkOption {
-        default = true;
-        example = false;
-        type = types.bool;
-        description = ''
-          If this is disabled, the build will fail whenever one of the
-          <command>udev</command> rules contains a reference to
-          <filename>/usr/bin</filename>, <filename>/usr/sbin</filename>,
-          <filename>/bin</filename> or <filename>/sbin</filename>.
-
-          By default only a warning is printed during build.
-        '';
-      };
-
     };
 
     hardware.firmware = mkOption {
diff --git a/nixos/tests/installer.nix b/nixos/tests/installer.nix
index cbfdad8d76b..84fdb027ed8 100644
--- a/nixos/tests/installer.nix
+++ b/nixos/tests/installer.nix
@@ -30,8 +30,6 @@ let
 
         hardware.enableAllFirmware = lib.mkForce false;
 
-        services.udev.allowImpurePaths = false;
-
         ${replaceChars ["\n"] ["\n  "] extraConfig}
       }
     '';
@@ -187,8 +185,6 @@ let
 
             hardware.enableAllFirmware = mkForce false;
 
-            services.udev.allowImpurePaths = false;
-
             # The test cannot access the network, so any packages we
             # need must be included in the VM.
             system.extraDependencies =