diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5be7515a3..7405f0f3a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,9 +4,11 @@
 
 ### Improvements
 - Fix the DICOM limit to say "Series" instead of "Studies" ([#1379](../../pull/1379))
+- Add token authentication option for DICOMweb ([#1349](../../pull/1349))
 
 ### Bug Fixes
 - Fix an issue applying ICC profile adjustments to multiple image modes ([#1382](../../pull/1382))
+- Guard against bad tifffile magnification values ([#1383](../../pull/1383))
 
 ## 1.26.1
 
diff --git a/sources/tifffile/large_image_source_tifffile/__init__.py b/sources/tifffile/large_image_source_tifffile/__init__.py
index 9aa70c18d..ab4d36bd3 100644
--- a/sources/tifffile/large_image_source_tifffile/__init__.py
+++ b/sources/tifffile/large_image_source_tifffile/__init__.py
@@ -125,12 +125,12 @@ def __init__(self, path, **kwargs):  # noqa
         try:
             unit = {2: 25.4, 3: 10}[page.tags['ResolutionUnit'].value.real]
 
-            if (page.tags['XResolution'].value[0] and (
-                    page.tags['XResolution'].value[1] / page.tags['XResolution'].value[0]) >= 100):
+            if (page.tags['XResolution'].value[0] and page.tags['XResolution'].value[1] and (
+                    page.tags['XResolution'].value[0] / page.tags['XResolution'].value[1]) >= 100):
                 self._mm_x = (unit * page.tags['XResolution'].value[1] /
                               page.tags['XResolution'].value[0])
-            if (page.tags['YResolution'].value[0] and (
-                    page.tags['YResolution'].value[1] / page.tags['YResolution'].value[0]) >= 100):
+            if (page.tags['YResolution'].value[0] and page.tags['YResolution'].value[1] and (
+                    page.tags['YResolution'].value[0] / page.tags['YResolution'].value[1]) >= 100):
                 self._mm_y = (unit * page.tags['YResolution'].value[1] /
                               page.tags['YResolution'].value[0])
         except Exception: