diff --git a/lib/overlays/version-info-fixup.nix b/lib/overlays/version-info-fixup.nix
index b413842..104840a 100644
--- a/lib/overlays/version-info-fixup.nix
+++ b/lib/overlays/version-info-fixup.nix
@@ -1,8 +1,8 @@
-{ inputs ? import ../../inputs.nix {} }:
+{ revision }:
 
 selfLib: superLib: {
   trivial = superLib.trivial // {
-    versionSuffix = ".git.${builtins.substring 0 12 inputs.lock.nixpkgs.revision}";
-    revisionWithDefault = default: inputs.lock.nixpkgs.revision or default;
+    versionSuffix = ".git.${builtins.substring 0 12 revision}";
+    revisionWithDefault = default: revision;
   };
 }
diff --git a/outputs.nix b/outputs.nix
index e1e2c24..225823d 100644
--- a/outputs.nix
+++ b/outputs.nix
@@ -5,7 +5,7 @@
 
 let
 
-lib = (import "${inputs.nixpkgs}/lib").extend (import ./lib/overlays/version-info-fixup.nix { inherit inputs; });
+lib = (import "${inputs.nixpkgs}/lib").extend (import ./lib/overlays/version-info-fixup.nix { revision = inputs.lock.nixpkgs.revision; });
 
 self = {
   inherit inputs lib self;
diff --git a/pkgs/overlays/version-info-fixup.nix b/pkgs/overlays/version-info-fixup.nix
index 14d890e..b1f2ecc 100644
--- a/pkgs/overlays/version-info-fixup.nix
+++ b/pkgs/overlays/version-info-fixup.nix
@@ -1,5 +1,12 @@
 { inputs ? import ../../inputs.nix {} }:
 
 self: super: {
-  lib = super.lib.extend (import ../../lib/overlays/version-info-fixup.nix { inherit inputs; });
+  lib = super.lib.extend (import ../../lib/overlays/version-info-fixup.nix { revision = inputs.lock.nixpkgs.revision; });
+} //
+super.lib.optionalAttrs (super ? unstable && super ? unstableRevision) {
+  unstable = super.unstable // {
+    lib = super.unstable.lib.extend (import ../../lib/overlays/version-info-fixup.nix {
+      revision = super.unstableRevision;
+    });
+  };
 }