diff --git a/manifest.dhall b/manifest.dhall
index dee2e8d8fc8731a193b3a5696b1e37a5be944a07..340a4b50b95d26157224c4141f812bf59de9ef80 100644
--- a/manifest.dhall
+++ b/manifest.dhall
@@ -306,7 +306,11 @@ in  [ callHackage "Cabal" "3.8.1.0"
     , callHackage "filemanip" "0.3.6.3"
     , callHackage "filepattern" "0.1.3"
     , callHackage "filtrable" "0.1.6.0"
-    , callHackage "fingertree-psqueue" "0.3"
+    , callCabal2nix
+        "fingertree-psqueue"
+        "https://gitlab.homotopic.tech/horizon/adopted/fingertree-psqueue"
+        (Some "d466b18e18d706dc1373ed2894c1e20ea2826329")
+        (None Text)
     , callHackage "fingertree" "0.1.5.0"
     , callHackage "finite-field" "0.10.0"
     , callHackage "first-class-families" "0.8.0.1"
diff --git a/pkgs/fingertree-psqueue.nix b/pkgs/fingertree-psqueue.nix
index 37493aea59af7760496bf7266cbc8e0c22b8b960..cb4ec2d04d95c4a0c85e7c36066df641c6b7780e 100644
--- a/pkgs/fingertree-psqueue.nix
+++ b/pkgs/fingertree-psqueue.nix
@@ -1,8 +1,13 @@
-{ mkDerivation, base, fingertree, lib }:
+{ mkDerivation, base, fetchgit, fingertree, lib }:
 mkDerivation {
   pname = "fingertree-psqueue";
   version = "0.3";
-  sha256 = "9f8c2f1965ea7a618d969db6506c8f373c95e09072b2182de40713d265046c92";
+  src = fetchgit {
+    url = "https://gitlab.homotopic.tech/horizon/adopted/fingertree-psqueue";
+    sha256 = "1h13yz23i3flx4mg8czk4k5ypx78q2lwfmmaljm54z3an1p4lv60";
+    rev = "d466b18e18d706dc1373ed2894c1e20ea2826329";
+    fetchSubmodules = true;
+  };
   isLibrary = true;
   isExecutable = false;
   enableSeparateDataOutput = false;