diff --git a/pkgs/by-name/ni/nixos-rebuild-ng/src/nixos_rebuild/models.py b/pkgs/by-name/ni/nixos-rebuild-ng/src/nixos_rebuild/models.py
index 54f2da06f7f0..d804a1c07ad6 100644
--- a/pkgs/by-name/ni/nixos-rebuild-ng/src/nixos_rebuild/models.py
+++ b/pkgs/by-name/ni/nixos-rebuild-ng/src/nixos_rebuild/models.py
@@ -86,7 +86,11 @@ class Flake:
 
     @override
     def __str__(self) -> str:
-        return f"{self.path}#{self.attr}"
+        if isinstance(self.path, Path):
+            # https://github.com/NixOS/nixpkgs/issues/433726
+            return f"{self.path.absolute()}#{self.attr}"
+        else:
+            return f"{self.path}#{self.attr}"
 
     @classmethod
     def parse(cls, flake_str: str, target_host: Remote | None = None) -> Self:
diff --git a/pkgs/by-name/ni/nixos-rebuild-ng/src/tests/test_models.py b/pkgs/by-name/ni/nixos-rebuild-ng/src/tests/test_models.py
index c2abc9501bb9..0663d73ef538 100644
--- a/pkgs/by-name/ni/nixos-rebuild-ng/src/tests/test_models.py
+++ b/pkgs/by-name/ni/nixos-rebuild-ng/src/tests/test_models.py
@@ -71,6 +71,14 @@ def test_flake_to_attr() -> None:
     )
 
 
+def test_flake__str__(monkeypatch: MonkeyPatch, tmpdir: Path) -> None:
+    assert str(m.Flake("github:nixos/nixpkgs", "attr")) == "github:nixos/nixpkgs#attr"
+    assert str(m.Flake(Path("/etc/nixos"), "attr")) == "/etc/nixos#attr"
+    with monkeypatch.context() as patch_context:
+        patch_context.chdir(tmpdir)
+        assert str(m.Flake(Path("."), "attr")) == f"{tmpdir}#attr"
+
+
 @patch("platform.node", autospec=True)
 def test_flake_from_arg(
     mock_node: Mock, monkeypatch: MonkeyPatch, tmpdir: Path
diff --git a/pkgs/by-name/ni/nixos-rebuild-ng/src/tests/test_nix.py b/pkgs/by-name/ni/nixos-rebuild-ng/src/tests/test_nix.py
index 639910e6620d..a61004a60d6a 100644
--- a/pkgs/by-name/ni/nixos-rebuild-ng/src/tests/test_nix.py
+++ b/pkgs/by-name/ni/nixos-rebuild-ng/src/tests/test_nix.py
@@ -54,7 +54,7 @@ def test_build(mock_run: Mock) -> None:
 )
 def test_build_flake(mock_run: Mock, monkeypatch: MonkeyPatch, tmpdir: Path) -> None:
     monkeypatch.chdir(tmpdir)
-    flake = m.Flake.parse(".#hostname")
+    flake = m.Flake.parse("/flake.nix#hostname")
 
     assert n.build_flake(
         "config.system.build.toplevel",
@@ -68,7 +68,7 @@ def test_build_flake(mock_run: Mock, monkeypatch: MonkeyPatch, tmpdir: Path) ->
             "nix-command flakes",
             "build",
             "--print-out-paths",
-            '.#nixosConfigurations."hostname".config.system.build.toplevel',
+            '/flake.nix#nixosConfigurations."hostname".config.system.build.toplevel',
             "--no-link",
             "--nix-flag",
             "foo",
@@ -173,7 +173,7 @@ def test_build_remote_flake(
     mock_run: Mock, monkeypatch: MonkeyPatch, tmpdir: Path
 ) -> None:
     monkeypatch.chdir(tmpdir)
-    flake = m.Flake.parse(".#hostname")
+    flake = m.Flake.parse("/flake.nix#hostname")
     build_host = m.Remote("user@host", [], None)
     monkeypatch.setenv("NIX_SSHOPTS", "--ssh opts")
 
@@ -194,7 +194,7 @@ def test_build_remote_flake(
                     "nix-command flakes",
                     "eval",
                     "--raw",
-                    '.#nixosConfigurations."hostname".config.system.build.toplevel.drvPath',
+                    '/flake.nix#nixosConfigurations."hostname".config.system.build.toplevel.drvPath',
                     "--flake",
                 ],
                 stdout=PIPE,
@@ -291,7 +291,7 @@ def test_edit(mock_run: Mock, monkeypatch: MonkeyPatch, tmpdir: Path) -> None:
 
 @patch(get_qualified_name(n.run_wrapper, n), autospec=True)
 def test_edit_flake(mock_run: Mock) -> None:
-    flake = m.Flake.parse(".#attr")
+    flake = m.Flake.parse("/flake.nix#attr")
     n.edit_flake(flake, {"commit_lock_file": True})
     mock_run.assert_called_with(
         [
@@ -301,7 +301,7 @@ def test_edit_flake(mock_run: Mock) -> None:
             "edit",
             "--commit-lock-file",
             "--",
-            '.#nixosConfigurations."attr"',
+            '/flake.nix#nixosConfigurations."attr"',
         ],
         check=False,
     )
@@ -385,7 +385,7 @@ def test_get_build_image_variants(mock_run: Mock, tmp_path: Path) -> None:
     ),
 )
 def test_get_build_image_variants_flake(mock_run: Mock) -> None:
-    flake = m.Flake(Path("flake.nix"), "myAttr")
+    flake = m.Flake(Path("/flake.nix"), "myAttr")
     assert n.get_build_image_variants_flake(flake, {"eval_flag": True}) == {
         "azure": "nixos-image-azure-25.05.20250102.6df2492-x86_64-linux.vhd",
         "vmware": "nixos-image-vmware-25.05.20250102.6df2492-x86_64-linux.vmdk",
@@ -395,7 +395,7 @@ def test_get_build_image_variants_flake(mock_run: Mock) -> None:
             "nix",
             "eval",
             "--json",
-            "flake.nix#myAttr.config.system.build.images",
+            "/flake.nix#myAttr.config.system.build.images",
             "--apply",
             "builtins.attrNames",
             "--eval-flag",