diff --git a/tests/test_2548.py b/tests/test_2548.py
index 46d5038df..2d354fdb0 100644
--- a/tests/test_2548.py
+++ b/tests/test_2548.py
@@ -32,7 +32,10 @@ def test_2548():
     # This checks that PyMuPDF 1.23.7 fixes this bug, and also that earlier
     # versions with updated MuPDF also fix the bug.
     rebased = hasattr(pymupdf, 'mupdf')
-    expected = 'format error: cycle in structure tree\nstructure tree broken, assume tree is missing'
+    if pymupdf.mupdf_version_tuple >= (1, 27):
+        expected = 'format error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing'
+    else:
+        expected = 'format error: cycle in structure tree\nstructure tree broken, assume tree is missing'
     if rebased:
         assert wt == expected, f'expected:\n    {expected!r}\nwt:\n    {wt!r}\n'
     assert not e
diff --git a/tests/test_textextract.py b/tests/test_textextract.py
index 944df1e86..46b137a37 100644
--- a/tests/test_textextract.py
+++ b/tests/test_textextract.py
@@ -377,6 +377,9 @@ def get_all_page_from_pdf(document, last_page=None):
     if pymupdf.mupdf_version_tuple < (1, 27):
         wt = pymupdf.TOOLS.mupdf_warnings()
         assert wt == 'Actualtext with no position. Text may be lost or mispositioned.\n... repeated 434 times...'
+    else:
+        wt = pymupdf.TOOLS.mupdf_warnings()
+        assert wt == 'format error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing\nformat error: No common ancestor in structure tree\nstructure tree broken, assume tree is missing'
 
 def test_3650():
     path = os.path.normpath(f'{__file__}/../../tests/resources/test_3650.pdf')