diff --git a/stubs/fanstatic/fanstatic/compiler.pyi b/stubs/fanstatic/fanstatic/compiler.pyi
index 0ecf68e74f45..20006784bdcb 100644
--- a/stubs/fanstatic/fanstatic/compiler.pyi
+++ b/stubs/fanstatic/fanstatic/compiler.pyi
@@ -2,7 +2,7 @@ from _typeshed import StrOrBytesPath
 from abc import abstractmethod
 from logging import Logger
 from subprocess import Popen
-from typing import Any, ClassVar
+from typing import Any, ClassVar, NewType
 from typing_extensions import Literal
 
 import setuptools.command.sdist
@@ -53,8 +53,10 @@ class NullCompiler(Compiler):
     @property
     def available(self) -> Literal[False]: ...
 
-SOURCE: object
-TARGET: object
+_SourceType = NewType("_SourceType", object)
+_TargetType = NewType("_TargetType", object)
+SOURCE: _SourceType
+TARGET: _TargetType
 
 class CommandlineBase:
     @property
@@ -63,13 +65,15 @@ class CommandlineBase:
     arguments: ClassVar[list[str]]
     @property
     def available(self) -> bool: ...
-    def process(self, source: StrOrBytesPath, target: StrOrBytesPath) -> Popen[str]: ...
+    def process(self, source: StrOrBytesPath | _SourceType, target: StrOrBytesPath | _TargetType) -> Popen[str]: ...
 
 class CoffeeScript(CommandlineBase, Compiler):
     name: ClassVar[Literal["coffee"]]
     command: ClassVar[Literal["coffee"]]
     source_extension = NotImplemented
-    def process(self, source: StrOrBytesPath, target: StrOrBytesPath) -> None: ...  # type:ignore[override]
+    def process(
+        self, source: StrOrBytesPath | _SourceType, target: StrOrBytesPath | _TargetType
+    ) -> None: ...  # type:ignore[override]
 
 COFFEE_COMPILER: CoffeeScript
 
diff --git a/stubs/fanstatic/fanstatic/core.pyi b/stubs/fanstatic/fanstatic/core.pyi
index 5885bab0e1e7..304c74328dad 100644
--- a/stubs/fanstatic/fanstatic/core.pyi
+++ b/stubs/fanstatic/fanstatic/core.pyi
@@ -2,6 +2,7 @@ from abc import abstractmethod
 from collections.abc import Callable, Iterable
 from threading import local
 from types import ModuleType
+from typing import NewType
 from typing_extensions import Literal, TypeAlias
 
 from fanstatic.compiler import Compiler, Minifier
@@ -96,7 +97,8 @@ class Asset(Dependable):
     def set_dependencies(self, depends: Iterable[Dependable] | None) -> None: ...
     def list_assets(self) -> set[Asset]: ...
 
-NOTHING: object
+_NothingType = NewType("_NothingType", object)
+NOTHING: _NothingType
 
 class Resource(Renderable, Asset):
     relpath: str
@@ -123,8 +125,8 @@ class Resource(Renderable, Asset):
         debug: str | Resource | None = None,
         dont_bundle: bool = False,
         minified: str | Resource | None = None,
-        minifier: Minifier = ...,
-        compiler: Compiler = ...,
+        minifier: Minifier | _NothingType = ...,
+        compiler: Compiler | _NothingType = ...,
         source: str | None = None,
         mode_parent: str | None = None,
     ) -> None: ...
@@ -134,7 +136,8 @@ class Resource(Renderable, Asset):
     def mode(self, mode: str | None) -> Resource: ...
     def need(self, slots: dict[Slot, Resource] | None = None) -> None: ...
 
-REQUIRED_DEFAULT_MARKER: object
+_RequiredDefaultMarkerType = NewType("_RequiredDefaultMarkerType", object)
+REQUIRED_DEFAULT_MARKER: _RequiredDefaultMarkerType
 
 class Slot(Asset):
     default: Resource | None
@@ -145,7 +148,7 @@ class Slot(Asset):
         library: Library,
         extension: str,
         depends: Iterable[Dependable] | None = None,
-        required: bool = ...,
+        required: bool | _RequiredDefaultMarkerType = ...,
         default: Resource | None = None,
     ) -> None: ...
 
diff --git a/stubs/fanstatic/fanstatic/injector.pyi b/stubs/fanstatic/fanstatic/injector.pyi
index 0b2fc5618802..e76a7c878c9b 100644
--- a/stubs/fanstatic/fanstatic/injector.pyi
+++ b/stubs/fanstatic/fanstatic/injector.pyi
@@ -2,7 +2,7 @@ from _typeshed.wsgi import StartResponse, WSGIApplication, WSGIEnvironment
 from abc import abstractmethod
 from collections.abc import Iterable
 from typing import Any
-from typing_extensions import Literal, TypedDict
+from typing_extensions import Literal, TypedDict, Unpack
 
 from fanstatic.core import Dependable, NeededResources, Resource
 from fanstatic.inclusion import Inclusion
@@ -35,8 +35,8 @@ class Injector:
     config: _NeededResourcesConfig
     injector: InjectorPlugin
     def __init__(
-        self, app: WSGIApplication, injector: InjectorPlugin | None = None, **config: Any
-    ) -> None: ...  # FIXME: Switch to Unpack[_NeededResourcesConfig]
+        self, app: WSGIApplication, injector: InjectorPlugin | None = None, **config: Unpack[_NeededResourcesConfig]
+    ) -> None: ...
     def __call__(self, environ: WSGIEnvironment, start_response: StartResponse) -> Iterable[bytes]: ...
 
 class InjectorPlugin:
diff --git a/stubs/fanstatic/fanstatic/publisher.pyi b/stubs/fanstatic/fanstatic/publisher.pyi
index 12ac3386c891..0e2ecf483e13 100644
--- a/stubs/fanstatic/fanstatic/publisher.pyi
+++ b/stubs/fanstatic/fanstatic/publisher.pyi
@@ -1,5 +1,5 @@
 from _typeshed import StrOrBytesPath
-from _typeshed.wsgi import StartResponse, WSGIApplication
+from _typeshed.wsgi import StartResponse, WSGIApplication, WSGIEnvironment
 from collections.abc import Iterable
 from typing import IO, Any
 from typing_extensions import Literal