diff --git a/src/documents/parsers.py b/src/documents/parsers.py
index 75256bbed..a669c20ac 100644
--- a/src/documents/parsers.py
+++ b/src/documents/parsers.py
@@ -79,7 +79,8 @@ _THUMBNAIL_MAX_WIDTH = 500
 _THUMBNAIL_MAX_HEIGHT = 5000
 # Used only when the page geometry cannot be read
 _THUMBNAIL_FALLBACK_DPI = 150
-# Matches the density the thumbnail was previously rendered at before scaling
+# Cap on the target density, applied before supersampling: a capped tiny page
+# is rasterized at twice this and halved to the size a 300 DPI render gave
 _THUMBNAIL_MAX_DPI = 300
 # Pages with known geometry are rendered at this multiple of the computed DPI
 # and downsampled with Lanczos, which keeps text noticeably crisper than
@@ -196,14 +197,16 @@ def _compute_thumbnail_dpi(in_path: Path, logging_group=None) -> tuple[int, int]
     dpi_for_height = _THUMBNAIL_MAX_HEIGHT * 72 / height_pts
     # The old pipeline rendered at 300 DPI and then shrank to fit, so only
     # pages too small to reach the thumbnail size even at 300 DPI end up
-    # smaller than it. Rounding up keeps the render at or above the target,
-    # so the shrink-only clamp in encode_thumbnail_webp trims it to exactly
-    # the thumbnail size instead of leaving it a few pixels short.
+    # smaller than it. Rounding up keeps the downsampled render at or above
+    # the target, so the shrink-only clamp in encode_thumbnail_webp trims it
+    # to exactly the thumbnail size instead of leaving it a few pixels short.
     dpi = max(
         1,
         math.ceil(min(_THUMBNAIL_MAX_DPI, dpi_for_width, dpi_for_height)),
     )
-    return dpi, _THUMBNAIL_SUPERSAMPLE
+    # A page so large it hits the 1 DPI floor is already oversized, so
+    # doubling it would only quadruple the pixel count for no benefit
+    return dpi, 1 if dpi == 1 else _THUMBNAIL_SUPERSAMPLE
 
 
 def _render_pdf_thumbnail(
diff --git a/src/documents/tests/test_parsers.py b/src/documents/tests/test_parsers.py
index 3531cec92..23155b60e 100644
--- a/src/documents/tests/test_parsers.py
+++ b/src/documents/tests/test_parsers.py
@@ -147,7 +147,11 @@ class TestComputeThumbnailDpi:
             pytest.param((612.0, 100000.0), (4, 2), id="tall-strip-height-bound"),
             pytest.param((200.0, 300.0), (180, 2), id="small-page-width-bound"),
             pytest.param((72.0, 72.0), (300, 2), id="tiny-page-capped-at-300"),
-            pytest.param((1000000.0, 1000000.0), (1, 2), id="huge-page-minimum-one"),
+            pytest.param(
+                (1000000.0, 1000000.0),
+                (1, 1),
+                id="huge-page-minimum-one-unsupersampled",
+            ),
             pytest.param(None, (150, 1), id="unreadable-geometry-fallback"),
         ],
     )
@@ -166,7 +170,8 @@ class TestComputeThumbnailDpi:
             - The thumbnail DPI is computed
         THEN:
             - The DPI is rounded up so the render reaches 500x5000, never
-              exceeds 300, is at least 1, and is supersampled 2x; an unknown
+              exceeds 300, is at least 1, and is supersampled 2x (except at the
+              1 DPI floor); an unknown
               size gives the plain 150 DPI fallback without supersampling
         """
         mocker.patch(
@@ -491,6 +496,7 @@ class TestEncodeThumbnailWebp:
             pytest.param((1001, 1401), 2, (500, 700), id="2x-odd-rounded"),
             pytest.param((1000, 1400), 1, (500, 700), id="no-supersample-clamped"),
             pytest.param((600, 800), 2, (300, 400), id="2x-small-not-enlarged"),
+            pytest.param((900, 1200), 2, (450, 600), id="2x-below-clamp"),
         ],
     )
     def test_supersampled_render_downsampled(