diff --git a/iohub/ndtiff.py b/iohub/ndtiff.py
index 65e44e15..81969b67 100644
--- a/iohub/ndtiff.py
+++ b/iohub/ndtiff.py
@@ -35,7 +35,7 @@ def __init__(self, data_path: str):
         self.channel_names = list(self.dataset.get_channel_names())
         self.stage_positions = self.mm_meta["Summary"]["StagePositions"]
         self.z_step_size = self.mm_meta["Summary"]["z-step_um"]
-        self.xy_pixel_size = self.mm_meta["Summary"]["PixelSize_um"]
+        self.xy_pixel_size = self.mm_meta["Summary"].get("PixelSize_um", 1.0)
 
     def _get_summary_metadata(self):
         pm_metadata = self.dataset.summary_metadata
diff --git a/iohub/upti.py b/iohub/upti.py
index 4eb29e8e..6cc3c212 100644
--- a/iohub/upti.py
+++ b/iohub/upti.py
@@ -10,7 +10,6 @@
 
 
 class UPTIReader(ReaderBase):
-
     """
     Reader for UPTI raw data.
     Accepts both new live UPTI and older UPTI format.
diff --git a/iohub/zarrfile.py b/iohub/zarrfile.py
index 3ca03818..0689e99f 100644
--- a/iohub/zarrfile.py
+++ b/iohub/zarrfile.py
@@ -13,7 +13,6 @@
 
 
 class ZarrReader(ReaderBase):
-
     """
     .. deprecated:: 0.0.1
         `ZarrReader` will be removed in future iohub releases,