diff --git a/backend/src/nodes/impl/upscale/auto_split.py b/backend/src/nodes/impl/upscale/auto_split.py
index 90ba28186..864d3e6e9 100644
--- a/backend/src/nodes/impl/upscale/auto_split.py
+++ b/backend/src/nodes/impl/upscale/auto_split.py
@@ -134,6 +134,7 @@ def _max_split(
     # and we only get to know this factor after the first successful upscale.
     result: TileBlender | None = None
     scale: int = 0
+    out_channels: int = 0
 
     restart = True
     while restart:
@@ -192,7 +193,7 @@ def _max_split(
                     break
 
                 # figure out by how much the image was upscaled by
-                up_h, up_w, _ = get_h_w_c(upscale_result)
+                up_h, up_w, up_c = get_h_w_c(upscale_result)
                 current_scale = up_h // padded_tile.height
                 assert current_scale > 0
                 assert padded_tile.height * current_scale == up_h
@@ -201,10 +202,11 @@ def _max_split(
                 if row_result is None:
                     # allocate the result image
                     scale = current_scale
+                    out_channels = up_c
                     row_result = TileBlender(
                         width=w * scale,
                         height=padded_tile.height * scale,
-                        channels=c,
+                        channels=out_channels,
                         direction=BlendDirection.X,
                         blend_fn=half_sin_blend_fn,
                         _prev=prev_row_result,
@@ -229,7 +231,7 @@ def _max_split(
                 result = TileBlender(
                     width=w * scale,
                     height=h * scale,
-                    channels=c,
+                    channels=out_channels,
                     direction=BlendDirection.Y,
                     blend_fn=half_sin_blend_fn,
                 )
diff --git a/backend/src/nodes/impl/upscale/exact_split.py b/backend/src/nodes/impl/upscale/exact_split.py
index 71f97d88b..4a4907b62 100644
--- a/backend/src/nodes/impl/upscale/exact_split.py
+++ b/backend/src/nodes/impl/upscale/exact_split.py
@@ -128,7 +128,7 @@ def _exact_split_without_padding(
     upscale: Callable[[np.ndarray, Region], np.ndarray],
     overlap: int,
 ) -> np.ndarray:
-    h, w, c = get_h_w_c(img)
+    h, w, _ = get_h_w_c(img)
     exact_w, exact_h = exact_size
     assert w >= exact_w and h >= exact_h
 
@@ -139,6 +139,7 @@ def _exact_split_without_padding(
     # and we only get to know this factor after the first successful upscale.
     result: TileBlender | None = None
     scale: int = 0
+    out_channels: int = 0
 
     regions = _exact_split_into_regions(w, h, exact_w, exact_h, overlap)
     for row in regions:
@@ -152,7 +153,7 @@ def _exact_split_without_padding(
             upscale_result = upscale(padded_tile.read_from(img), padded_tile)
 
             # figure out by how much the image was upscaled by
-            up_h, up_w, _ = get_h_w_c(upscale_result)
+            up_h, up_w, up_c = get_h_w_c(upscale_result)
             current_scale = up_h // exact_h
             assert current_scale > 0
             assert exact_h * current_scale == up_h
@@ -161,10 +162,11 @@ def _exact_split_without_padding(
             if row_result is None:
                 # allocate the result image
                 scale = current_scale
+                out_channels = up_c
                 row_result = TileBlender(
                     width=w * scale,
                     height=exact_h * scale,
-                    channels=c,
+                    channels=out_channels,
                     direction=BlendDirection.X,
                     blend_fn=half_sin_blend_fn,
                 )
@@ -182,7 +184,7 @@ def _exact_split_without_padding(
             result = TileBlender(
                 width=w * scale,
                 height=h * scale,
-                channels=c,
+                channels=out_channels,
                 direction=BlendDirection.Y,
                 blend_fn=half_sin_blend_fn,
             )