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 267ac3357450..c79052f3752f 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
@@ -52,7 +52,7 @@ class BuildAttr:
     attr: str | None
 
     def to_attr(self, *attrs: str) -> str:
-        return f"{self.attr + '.' if self.attr else ''}{".".join(attrs)}"
+        return f"{self.attr + '.' if self.attr else ''}{'.'.join(attrs)}"
 
     @classmethod
     def from_arg(cls, attr: str | None, file: str | None) -> Self:
@@ -68,7 +68,7 @@ class Flake:
     _re: ClassVar = re.compile(r"^(?P<path>[^\#]*)\#?(?P<attr>[^\#\"]*)$")
 
     def to_attr(self, *attrs: str) -> str:
-        return f"{self}.{".".join(attrs)}"
+        return f"{self}.{'.'.join(attrs)}"
 
     @override
     def __str__(self) -> str:
@@ -83,7 +83,7 @@ class Flake:
         m = cls._re.match(flake_str)
         assert m is not None, f"got no matches for {flake_str}"
         attr = m.group("attr")
-        nixos_attr = f"nixosConfigurations.{attr or hostname_fn() or "default"}"
+        nixos_attr = f"nixosConfigurations.{attr or hostname_fn() or 'default'}"
         path = m.group("path")
         if ":" in path:
             return cls(path, nixos_attr)
diff --git a/pkgs/by-name/ni/nixos-rebuild-ng/src/nixos_rebuild/process.py b/pkgs/by-name/ni/nixos-rebuild-ng/src/nixos_rebuild/process.py
index 54c8b71036e9..8905ab274508 100644
--- a/pkgs/by-name/ni/nixos-rebuild-ng/src/nixos_rebuild/process.py
+++ b/pkgs/by-name/ni/nixos-rebuild-ng/src/nixos_rebuild/process.py
@@ -15,7 +15,7 @@ SSH_DEFAULT_OPTS: Final = [
     "-o",
     "ControlMaster=auto",
     "-o",
-    f"ControlPath={tmpdir.TMPDIR_PATH / "ssh-%n"}",
+    f"ControlPath={tmpdir.TMPDIR_PATH / 'ssh-%n'}",
     "-o",
     "ControlPersist=60",
 ]