diff --git a/lib/default.nix b/lib/default.nix
index ccae0bbc3ab4..ccfee2ebe303 100644
--- a/lib/default.nix
+++ b/lib/default.nix
@@ -115,8 +115,8 @@ let
       mergeModules' mergeOptionDecls evalOptionValue mergeDefinitions
       pushDownProperties dischargeProperties filterOverrides
       sortProperties fixupOptionType mkIf mkAssert mkMerge mkOverride
-      mkOptionDefault mkDefault mkForce mkVMOverride mkStrict
-      mkFixStrictness mkOrder mkBefore mkAfter mkAliasDefinitions
+      mkOptionDefault mkDefault mkForce mkVMOverride
+      mkOrder mkBefore mkAfter mkAliasDefinitions
       mkAliasAndWrapDefinitions fixMergeModules mkRemovedOptionModule
       mkRenamedOptionModule mkMergedOptionModule mkChangedOptionModule
       mkAliasOptionModule doRename;
diff --git a/lib/modules.nix b/lib/modules.nix
index 99b9a8a31eac..58c6cda58e49 100644
--- a/lib/modules.nix
+++ b/lib/modules.nix
@@ -713,10 +713,6 @@ rec {
   mkForce = mkOverride 50;
   mkVMOverride = mkOverride 10; # used by ‘nixos-rebuild build-vm’
 
-  mkStrict = builtins.trace "`mkStrict' is obsolete; use `mkOverride 0' instead." (mkOverride 0);
-
-  mkFixStrictness = id; # obsolete, no-op
-
   mkOrder = priority: content:
     { _type = "order";
       inherit priority content;