diff --git a/invokeai/backend/generator/base.py b/invokeai/backend/generator/base.py
index e30b77ec33..ee56077fa8 100644
--- a/invokeai/backend/generator/base.py
+++ b/invokeai/backend/generator/base.py
@@ -21,7 +21,7 @@ from PIL import Image, ImageChops, ImageFilter
 from accelerate.utils import set_seed
 from diffusers import DiffusionPipeline
 from tqdm import trange
-from typing import List, Iterator, Type
+from typing import Callable, List, Iterator, Optional, Type
 from dataclasses import dataclass, field
 from diffusers.schedulers import SchedulerMixin as Scheduler
 
@@ -35,23 +35,23 @@ downsampling = 8
 
 @dataclass
 class InvokeAIGeneratorBasicParams:
-    seed: int=None
+    seed: Optional[int]=None
     width: int=512
     height: int=512
-    cfg_scale: int=7.5
+    cfg_scale: float=7.5
     steps: int=20
     ddim_eta: float=0.0
-    scheduler: int='ddim'
+    scheduler: str='ddim'
     precision: str='float16'
     perlin: float=0.0
-    threshold: int=0.0
+    threshold: float=0.0
     seamless: bool=False
     seamless_axes: List[str]=field(default_factory=lambda: ['x', 'y'])
-    h_symmetry_time_pct: float=None
-    v_symmetry_time_pct: float=None
+    h_symmetry_time_pct: Optional[float]=None
+    v_symmetry_time_pct: Optional[float]=None
     variation_amount: float = 0.0
     with_variations: list=field(default_factory=list)
-    safety_checker: SafetyChecker=None
+    safety_checker: Optional[SafetyChecker]=None
 
 @dataclass
 class InvokeAIGeneratorOutput:
@@ -61,10 +61,10 @@ class InvokeAIGeneratorOutput:
     and the model hash, as well as all the generate() parameters that went into
     generating the image (in .params, also available as attributes)
     '''
-    image: Image
+    image: Image.Image
     seed: int
     model_hash: str
-    attention_maps_images: List[Image]
+    attention_maps_images: List[Image.Image]
     params: Namespace
 
 # we are interposing a wrapper around the original Generator classes so that
@@ -92,8 +92,8 @@ class InvokeAIGenerator(metaclass=ABCMeta):
 
     def generate(self,
                  prompt: str='',
-                 callback: callable=None,
-                 step_callback: callable=None,
+                 callback: Optional[Callable]=None,
+                 step_callback: Optional[Callable]=None,
                  iterations: int=1,
                  **keyword_args,
                  )->Iterator[InvokeAIGeneratorOutput]:
@@ -206,10 +206,10 @@ class Txt2Img(InvokeAIGenerator):
 # ------------------------------------
 class Img2Img(InvokeAIGenerator):
     def generate(self,
-               init_image: Image | torch.FloatTensor,
+               init_image: Image.Image | torch.FloatTensor,
                strength: float=0.75,
                **keyword_args
-               )->List[InvokeAIGeneratorOutput]:
+               )->Iterator[InvokeAIGeneratorOutput]:
         return super().generate(init_image=init_image,
                                 strength=strength,
                                 **keyword_args
@@ -223,7 +223,7 @@ class Img2Img(InvokeAIGenerator):
 # Takes all the arguments of Img2Img and adds the mask image and the seam/infill stuff
 class Inpaint(Img2Img):
     def generate(self,
-                 mask_image: Image | torch.FloatTensor,
+                 mask_image: Image.Image | torch.FloatTensor,
                  # Seam settings - when 0, doesn't fill seam
                  seam_size: int = 0,
                  seam_blur: int = 0,
@@ -236,7 +236,7 @@ class Inpaint(Img2Img):
                  inpaint_height=None,
                  inpaint_fill: tuple(int) = (0x7F, 0x7F, 0x7F, 0xFF),
                  **keyword_args
-                 )->List[InvokeAIGeneratorOutput]:
+                 )->Iterator[InvokeAIGeneratorOutput]:
         return super().generate(
             mask_image=mask_image,
             seam_size=seam_size,
@@ -263,7 +263,7 @@ class Embiggen(Txt2Img):
             embiggen: list=None,
             embiggen_tiles: list = None,
             strength: float=0.75,
-            **kwargs)->List[InvokeAIGeneratorOutput]:
+            **kwargs)->Iterator[InvokeAIGeneratorOutput]:
         return super().generate(embiggen=embiggen,
                                 embiggen_tiles=embiggen_tiles,
                                 strength=strength,