diff --git a/userscript/manga-bookmark.user.js b/userscript/manga-bookmark.user.js
index d2933c8..bec8d4a 100644
--- a/userscript/manga-bookmark.user.js
+++ b/userscript/manga-bookmark.user.js
@@ -29,6 +29,10 @@
   // with its own prefix, so the two never share a cache, a queue or a panel.
   const STORE_PREFIX = "bmgr:manga:";
 
+  // Which library this script's rows belong to. The novel script is a separate
+  // install that declares "novel"; the backend keeps whichever it is told.
+  const LIBRARY = "manga";
+
   // Safe in Bromite's isolated world: the page's own JS cannot read these.
   const CACHE_KEY = STORE_PREFIX + "cache";
 
@@ -518,7 +522,9 @@
   }
 
   function setList(list) {
-    state.list = Array.isArray(list) ? list : [];
+    // GET /bookmarks answers with every library; this panel owns one of them,
+    // and the cache must not hold rows it can never show.
+    state.list = (Array.isArray(list) ? list : []).filter((b) => kindOf(b) === LIBRARY);
     reindex();
     saveCache(state.list);
   }
@@ -543,6 +549,12 @@
     return b.status || "reading";
   }
 
+  // A list cached by an older version has no kind field, and a row the server
+  // defaulted has "manga" — both mean the same thing here.
+  function kindOf(b) {
+    return b.kind || "manga";
+  }
+
   // ============================================================
   // Retry queue
   //
@@ -827,6 +839,7 @@
     const bm = {
       key: key,
       site: p.site,
+      kind: LIBRARY,
       series_id: p.seriesId,
       title: p.title || (existing && existing.title) || p.seriesId,
       series_url: p.seriesUrl || (existing && existing.series_url) || "",
@@ -849,6 +862,7 @@
     const bm = Object.assign({}, existing, {
       key: key,
       site: p.site,
+      kind: LIBRARY,
       series_id: p.seriesId,
       title: existing.title || p.title || p.seriesId,
       series_url: existing.series_url || p.seriesUrl || "",
@@ -1799,7 +1813,7 @@
   // Exposes pure logic only — see userscript/test/logic.test.js.
   // ============================================================
   if (typeof window === "undefined" && typeof module === "object" && module.exports) {
-    module.exports = { stripBuildHash, comixSeriesId, asura, demonic, comix, kagane, anchorsFromHTML, statusOf };
+    module.exports = { stripBuildHash, comixSeriesId, asura, demonic, comix, kagane, anchorsFromHTML, statusOf, kindOf };
   }
 
   // ============================================================
diff --git a/userscript/test/logic.test.js b/userscript/test/logic.test.js
index f6b96c3..73230d0 100644
--- a/userscript/test/logic.test.js
+++ b/userscript/test/logic.test.js
@@ -60,6 +60,7 @@ const {
   kagane,
   anchorsFromHTML,
   statusOf,
+  kindOf,
 } = require("../manga-bookmark.user.js");
 
 // detect() reads only these four properties off location.
@@ -377,3 +378,17 @@ test("statusOf defaults a missing status to reading", () => {
   assert.equal(statusOf({ status: "archived" }), "archived");
   assert.equal(statusOf({ status: "finished" }), "finished");
 });
+
+// ============================================================
+// kindOf — a row written before the kind column existed has none, and every
+// one of those is manga.
+// ============================================================
+
+test("kindOf defaults a missing kind to manga", () => {
+  assert.equal(kindOf({}), "manga");
+  assert.equal(kindOf({ kind: "" }), "manga");
+});
+
+test("kindOf passes through an explicit kind", () => {
+  assert.equal(kindOf({ kind: "novel" }), "novel");
+});