diff --git a/pyWebLayout/layout/ereader_layout.py b/pyWebLayout/layout/ereader_layout.py
index 0fb46b0..1888a01 100644
--- a/pyWebLayout/layout/ereader_layout.py
+++ b/pyWebLayout/layout/ereader_layout.py
@@ -857,27 +857,3 @@ class BidirectionalLayouter:
         if pos1.word_index != pos2.word_index:
             return 1 if pos1.word_index > pos2.word_index else -1
         return 0
-
-
-# Add can_fit_line method to Page class if it doesn't exist
-def _add_page_methods():
-    """Add missing methods to Page class"""
-    if not hasattr(Page, 'can_fit_line'):
-        def can_fit_line(self, line_height: int) -> bool:
-            """Check if a line of given height can fit on the page"""
-            available_height = self.content_size[1] - self._current_y_offset
-            return available_height >= line_height
-
-        Page.can_fit_line = can_fit_line
-
-    if not hasattr(Page, 'available_width'):
-        @property
-        def available_width(self) -> int:
-            """Get available width for content"""
-            return self.content_size[0]
-
-        Page.available_width = available_width
-
-
-# Apply the page methods
-_add_page_methods()
diff --git a/tests/layout/test_ereader_layout.py b/tests/layout/test_ereader_layout.py
index 09513ab..5436514 100644
--- a/tests/layout/test_ereader_layout.py
+++ b/tests/layout/test_ereader_layout.py
@@ -899,5 +899,43 @@ class TestBidirectionalLayouter:
         assert next_pos == position  # No progress possible
 
 
+class TestNoPageMonkeyPatching:
+    """
+    R5: importing this module used to run _add_page_methods(), which attached
+    can_fit_line/available_width to Page if they were absent. They are not
+    absent, so it never fired - but its can_fit_line took (line_height) and
+    ignored descenders, while Page's takes (baseline_spacing, ascent, descent).
+    Had Page's ever been renamed, the import would have silently reinstated the
+    pre-S2 clipping bug from another package.
+    """
+
+    def test_module_does_not_patch_page(self):
+        import pyWebLayout.layout.ereader_layout as ereader_layout
+
+        assert not hasattr(ereader_layout, '_add_page_methods')
+
+    def test_page_owns_its_geometry_methods(self):
+        from pyWebLayout.concrete.page import Page
+
+        assert 'can_fit_line' in vars(Page)
+        assert 'available_width' in vars(Page)
+
+    def test_can_fit_line_still_accounts_for_descenders(self, sample_page_style):
+        """
+        The patched version took a single line_height and had no way to express
+        descent, so a descender hanging past the content box counted as fitting.
+        """
+        from pyWebLayout.concrete.page import Page
+
+        page = Page(size=(200, 100), style=sample_page_style)
+        content_y, content_h = page.content_rect[1], page.content_rect[3]
+        available = content_y + content_h - page._current_y_offset
+
+        assert page.can_fit_line(0, ascent=available, descent=0)
+        assert not page.can_fit_line(0, ascent=available, descent=1), \
+            "a descender past the content box must not be reported as fitting"
+        assert page.can_fit_line(0, ascent=available - 1, descent=1)
+
+
 if __name__ == "__main__":
     pytest.main([__file__, "-v"])