diff --git a/diagram/prolly-s3-architecture.svg b/diagram/prolly-s3-architecture.svg
index d19987e..ec0dece 100644
--- a/diagram/prolly-s3-architecture.svg
+++ b/diagram/prolly-s3-architecture.svg
@@ -4,7 +4,8 @@
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   <text x="50" y="55" class="h">Prolly is the history; S3 holds whole immutable payloads</text>
@@ -36,7 +37,7 @@
   <text x="785" y="534" class="b">retention pins + exact-version GC</text>
   <path d="M260 235H350" class="line"/><text x="305" y="222" text-anchor="middle" class="s">calls</text>
   <path d="M650 185H755" class="line"/><text x="702" y="169" text-anchor="middle" class="s">whole bytes</text>
-  <path d="M650 290C705 290 720 430 755 440" class="line"/><text x="690" y="365" text-anchor="middle" class="s">history</text>
+  <path d="M650 290C705 290 720 430 755 440" class="line history-line"/><text x="690" y="365" text-anchor="middle" class="s">history</text>
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   <text x="80" y="468" class="t">Canonical read</text>
   <text x="80" y="500" class="b">1. Pin a Prolly commit and resolve the logical key.</text>