diff --git a/.changeset/dirty-lizards-explode.md b/.changeset/dirty-lizards-explode.md
new file mode 100644
index 0000000000..eb799df63f
--- /dev/null
+++ b/.changeset/dirty-lizards-explode.md
@@ -0,0 +1,5 @@
+---
+"@siteimprove/alfa-dom": patch
+---
+
+**Fixed:** Parents of `Comment` inside a shadow tree now correctly skip over the shadow root when traversing the flat tree.
diff --git a/docs/review/api/alfa-dom.api.md b/docs/review/api/alfa-dom.api.md
index b758b4d793..385c50523b 100644
--- a/docs/review/api/alfa-dom.api.md
+++ b/docs/review/api/alfa-dom.api.md
@@ -289,8 +289,6 @@ export class Element<N extends string = string> extends Node<"element"> implemen
     // (undocumented)
     static of<N extends string = string>(namespace: Option<Namespace>, prefix: Option<string>, name: N, attributes?: Iterable_2<Attribute>, children?: Iterable_2<Node>, style?: Option<Block>, box?: Option<Rectangle>, device?: Option<Device>, externalId?: string, extraData?: any): Element<N>;
     // (undocumented)
-    parent(options?: Node.Traversal): Option<Node>;
-    // (undocumented)
     get prefix(): Option<string>;
     // (undocumented)
     get qualifiedName(): string;
@@ -1149,8 +1147,6 @@ export class Text extends Node<"text"> implements Slotable {
     // (undocumented)
     static of(data: string, externalId?: string, extraData?: any): Text;
     // (undocumented)
-    parent(options?: Node.Traversal): Option<Node>;
-    // (undocumented)
     toJSON(): Text.JSON;
     // (undocumented)
     toString(): string;
diff --git a/packages/alfa-dom/src/node.ts b/packages/alfa-dom/src/node.ts
index 9aecde7f7c..9c85730e97 100644
--- a/packages/alfa-dom/src/node.ts
+++ b/packages/alfa-dom/src/node.ts
@@ -22,6 +22,7 @@ import {
   Fragment,
   Shadow,
   Slot,
+  Slotable,
   Text,
   Type,
 } from ".";
@@ -135,6 +136,33 @@ export abstract class Node<T extends string = string>
       });
   }
 
+  public parent(options: Node.Traversal = Node.Traversal.empty): Option<Node> {
+    const parent = this._parent as Option<Node>;
+
+    // If we traverse the flat tree, we want to jump over shadow roots.
+    if (options.isSet(Node.Traversal.flattened)) {
+      return parent.flatMap((parent) => {
+        if (Shadow.isShadow(parent)) {
+          return parent.host;
+        }
+
+        // Additionally, if this is a slottable light child of a shadow host, we want
+        // to search for where it is slotted, and return that parent instead.
+        if (
+          Element.isElement(parent) &&
+          parent.shadow.isSome() &&
+          Slotable.isSlotable(this)
+        ) {
+          return this.assignedSlot().flatMap((slot) => slot.parent(options));
+        }
+
+        return Option.of(parent);
+      });
+    }
+
+    return parent;
+  }
+
   private _path: Array<string> = [];
 
   /**
diff --git a/packages/alfa-dom/src/node/element.ts b/packages/alfa-dom/src/node/element.ts
index c02c9c7162..a981f2d359 100644
--- a/packages/alfa-dom/src/node/element.ts
+++ b/packages/alfa-dom/src/node/element.ts
@@ -161,26 +161,6 @@ export class Element<N extends string = string>
     return this._boxes.get(device);
   }
 
-  public parent(options: Node.Traversal = Node.Traversal.empty): Option<Node> {
-    const parent = this._parent as Option<Node>;
-
-    if (options.isSet(Node.Traversal.flattened)) {
-      return parent.flatMap((parent) => {
-        if (Shadow.isShadow(parent)) {
-          return parent.host;
-        }
-
-        if (Element.isElement(parent) && parent.shadow.isSome()) {
-          return this.assignedSlot().flatMap((slot) => slot.parent(options));
-        }
-
-        return Option.of(parent);
-      });
-    }
-
-    return parent;
-  }
-
   public children(
     options: Node.Traversal = Node.Traversal.empty,
   ): Sequence<Node> {
diff --git a/packages/alfa-dom/src/node/shadow.ts b/packages/alfa-dom/src/node/shadow.ts
index ee6ed5fed0..ea28639981 100644
--- a/packages/alfa-dom/src/node/shadow.ts
+++ b/packages/alfa-dom/src/node/shadow.ts
@@ -61,6 +61,8 @@ export class Shadow extends Node<"shadow"> {
   }
 
   public parent(options: Node.Traversal = Node.Traversal.empty): Option<Node> {
+    // We only "land" on Shadow roots when traversing the composed tree.
+    // Notably, flattening the tree "jumps" over them.
     if (options.isSet(Node.Traversal.composed)) {
       return this._host;
     }
diff --git a/packages/alfa-dom/src/node/text.ts b/packages/alfa-dom/src/node/text.ts
index db4a2e86b0..1267ce6bb9 100644
--- a/packages/alfa-dom/src/node/text.ts
+++ b/packages/alfa-dom/src/node/text.ts
@@ -2,8 +2,6 @@ import { Option } from "@siteimprove/alfa-option";
 import { Trampoline } from "@siteimprove/alfa-trampoline";
 
 import { Node } from "../node";
-import { Element } from "./element";
-import { Shadow } from "./shadow";
 import { Slot } from "./slot";
 import { Slotable } from "./slotable";
 
@@ -31,26 +29,6 @@ export class Text extends Node<"text"> implements Slotable {
     return this._data;
   }
 
-  public parent(options: Node.Traversal = Node.Traversal.empty): Option<Node> {
-    const parent = this._parent as Option<Node>;
-
-    if (options.isSet(Node.Traversal.flattened)) {
-      return parent.flatMap((parent) => {
-        if (Shadow.isShadow(parent)) {
-          return parent.host;
-        }
-
-        if (Element.isElement(parent) && parent.shadow.isSome()) {
-          return this.assignedSlot().flatMap((slot) => slot.parent(options));
-        }
-
-        return Option.of(parent);
-      });
-    }
-
-    return parent;
-  }
-
   public assignedSlot(): Option<Slot> {
     return Slotable.findSlot(this);
   }
diff --git a/packages/alfa-dom/src/node/traversal/get-nodes-between.ts b/packages/alfa-dom/src/node/traversal/get-nodes-between.ts
index 105279fc0e..0897bf9448 100755
--- a/packages/alfa-dom/src/node/traversal/get-nodes-between.ts
+++ b/packages/alfa-dom/src/node/traversal/get-nodes-between.ts
@@ -1,6 +1,6 @@
-import { Node } from "../..";
 import { Predicate } from "@siteimprove/alfa-predicate";
 import { Sequence } from "@siteimprove/alfa-sequence";
+import { Node } from "../..";
 
 import { lowestCommonAncestor } from "./lowest-common-ancestor";
 
@@ -43,7 +43,7 @@ export function getNodesBetween(
     // of the closest ancestor having one.
     between = first
       // Closest ancestor with a next sibling.
-      .closest((ancestor) => ancestor.next(treeOptions).isSome())
+      .closest((ancestor) => ancestor.next(treeOptions).isSome(), treeOptions)
       // Get that sibling.
       .flatMap((node) => node.next(treeOptions))
       // Skip everything until next.
@@ -71,7 +71,6 @@ function getNodesInclusivelyBetween(
 ): Sequence<Node> {
   const isFrontier = or(equals(node1), equals(node2));
 
-  // Get descendants of the LCA, and skip everything before and after both nodes.
   return lowestCommonAncestor(node1, node2, treeOptions)
     .map((context) =>
       context
diff --git a/packages/alfa-dom/test/traversal.spec.tsx b/packages/alfa-dom/test/traversal.spec.tsx
new file mode 100644
index 0000000000..33c1b1922a
--- /dev/null
+++ b/packages/alfa-dom/test/traversal.spec.tsx
@@ -0,0 +1,66 @@
+import { None } from "@siteimprove/alfa-option";
+import { test } from "@siteimprove/alfa-test";
+
+import { h, Comment, Node } from "../src";
+
+const targets = [<span />, h.text("hello"), Comment.of("world")];
+const shadow = h.shadow(targets);
+const div = <div>{shadow}</div>;
+
+// Start with no flag.
+// For each of the three flags, duplicate existing list and add the flag to one side.
+// This ends up giving the eight possible options.
+const flags = [
+  Node.Traversal.composed,
+  Node.Traversal.flattened,
+  Node.Traversal.nested,
+].reduce(
+  (old, cur) => old.flatMap((flag) => [flag, flag.add(cur)]),
+  [Node.Traversal.of(Node.Traversal.none)],
+);
+
+test(".parent() of a shadow host returns None in composed traversal, the shadow root otherwise", (t) => {
+  for (const traversal of flags) {
+    if (traversal.has(Node.Traversal.composed)) {
+      t.deepEqual(shadow.parent(traversal).getUnsafe(), div);
+    } else {
+      t.deepEqual(shadow.parent(traversal), None);
+    }
+  }
+});
+
+test(".parent() of the children of a shadow root returns the shadow host in flat traversal, the shadow root otherwise", (t) => {
+  for (const target of targets) {
+    for (const traversal of flags) {
+      if (traversal.has(Node.Traversal.flattened)) {
+        t.deepEqual(target.parent(traversal).getUnsafe(), div);
+      } else {
+        t.deepEqual(target.parent(traversal).getUnsafe(), shadow);
+      }
+    }
+  }
+});
+
+test(".parent() of a slottable child of a shadow host returns the slot's parent in flat traversal, the light parent otherwise", (t) => {
+  const target = <span slot="foo" />;
+  const shadowDiv = (
+    <div>
+      <slot name="foo"></slot>
+    </div>
+  );
+  const shadow = h.shadow([shadowDiv]);
+  const lightDiv = (
+    <div>
+      {shadow}
+      {target}
+    </div>
+  );
+
+  for (const traversal of flags) {
+    if (traversal.has(Node.Traversal.flattened)) {
+      t.deepEqual(target.parent(traversal).getUnsafe(), shadowDiv);
+    } else {
+      t.deepEqual(target.parent(traversal).getUnsafe(), lightDiv);
+    }
+  }
+});
diff --git a/packages/alfa-dom/tsconfig.json b/packages/alfa-dom/tsconfig.json
index 6eba504794..a096aaf300 100644
--- a/packages/alfa-dom/tsconfig.json
+++ b/packages/alfa-dom/tsconfig.json
@@ -86,7 +86,8 @@
     "test/node/traversal/get-nodes-between.spec.tsx",
     "test/node/traversal/lowest-common-ancestor.spec.tsx",
     "test/node/query/element-descendants.spec.tsx",
-    "test/node/query/element-id-map.spec.tsx"
+    "test/node/query/element-id-map.spec.tsx",
+    "test/traversal.spec.tsx"
   ],
   "references": [
     { "path": "../alfa-array" },
@@ -103,7 +104,7 @@
     { "path": "../alfa-map" },
     { "path": "../alfa-option" },
     { "path": "../alfa-predicate" },
-    { "path": "../alfa-rectangle"},
+    { "path": "../alfa-rectangle" },
     { "path": "../alfa-refinement" },
     { "path": "../alfa-sarif" },
     { "path": "../alfa-selective" },
diff --git a/yarn.lock b/yarn.lock
index 6f549c5b8a..60cb50f81c 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -406,9 +406,9 @@ __metadata:
   linkType: hard
 
 "@mdn/browser-compat-data@npm:^5.0.0":
-  version: 5.5.4
-  resolution: "@mdn/browser-compat-data@npm:5.5.4"
-  checksum: bdef5c85cc6e90bbf6e873033bfcf92dba2df699fb9fdd7390f5d1dc0e6d14fba9b8b3585370248a82913585eb1792c1afd20900efb6604c9e59122ba98060d7
+  version: 5.5.6
+  resolution: "@mdn/browser-compat-data@npm:5.5.6"
+  checksum: b22f1d9e69451c12295b0ead856dd5d12b08f43a068047bc8e40f365fd8b41207a96e2a5383048a0b6e87daa0edc4e8cbdaf70e1e593b653e347178a85b30530
   languageName: node
   linkType: hard
 
@@ -2092,11 +2092,11 @@ __metadata:
   linkType: hard
 
 "@types/node@npm:*, @types/node@npm:^20.5.9":
-  version: 20.10.7
-  resolution: "@types/node@npm:20.10.7"
+  version: 20.11.1
+  resolution: "@types/node@npm:20.11.1"
   dependencies:
     undici-types: "npm:~5.26.4"
-  checksum: d626cea1b7da4784ee7b335dcc54e64adba9725dab7ca51a690167de502ef89fec07b05ad8e25845d188d7ad7f72c192ec92964d456321ed5b9452113bf9351f
+  checksum: f665cdce28b0b6e57338d1f74e0599ee9b10eac74cff729921c8f473807398e9aba2f8cf74c74a4d3dfbc2d616c73267da7de3003ed3c8152ea366bf4c96a91a
   languageName: node
   linkType: hard
 
@@ -2663,13 +2663,6 @@ __metadata:
   languageName: node
   linkType: hard
 
-"chalk@npm:^5.3.0":
-  version: 5.3.0
-  resolution: "chalk@npm:5.3.0"
-  checksum: 8297d436b2c0f95801103ff2ef67268d362021b8210daf8ddbe349695333eb3610a71122172ff3b0272f1ef2cf7cc2c41fdaa4715f52e49ffe04c56340feed09
-  languageName: node
-  linkType: hard
-
 "chardet@npm:^0.7.0":
   version: 0.7.0
   resolution: "chardet@npm:0.7.0"
@@ -4593,8 +4586,8 @@ __metadata:
   linkType: hard
 
 "knip@npm:^3.0.0":
-  version: 3.12.0
-  resolution: "knip@npm:3.12.0"
+  version: 3.13.2
+  resolution: "knip@npm:3.13.2"
   dependencies:
     "@ericcornelissen/bash-parser": "npm:0.5.2"
     "@npmcli/map-workspaces": "npm:3.0.4"
@@ -4603,7 +4596,6 @@ __metadata:
     "@pnpm/logger": "npm:5.0.0"
     "@pnpm/workspace.pkgs-graph": "npm:^2.0.13"
     "@snyk/github-codeowners": "npm:1.1.0"
-    chalk: "npm:^5.3.0"
     easy-table: "npm:1.2.0"
     fast-glob: "npm:3.3.2"
     globby: "npm:^14.0.0"
@@ -4611,6 +4603,7 @@ __metadata:
     js-yaml: "npm:4.1.0"
     micromatch: "npm:4.0.5"
     minimist: "npm:1.2.8"
+    picocolors: "npm:1.0.0"
     pretty-ms: "npm:8.0.0"
     strip-json-comments: "npm:5.0.1"
     summary: "npm:2.1.0"
@@ -4621,7 +4614,7 @@ __metadata:
     typescript: ">=5.0.4"
   bin:
     knip: bin/knip.js
-  checksum: 29599ebb99d369154320aa6ab9bb0d24a1eb3ff8386593e8bef6fb5481eb1ed59a00bf490d43495a07a5164d21c8bbd3c5a79c24a74cdb1e12ae2855918c8901
+  checksum: 9221fa8d863d298ad642fd379e0e8df7f160663e773591e226b46d73219e9a3679528fdc405071b8a3741f7b87491017b496331179db272df2db1945ea91c40d
   languageName: node
   linkType: hard
 
@@ -5645,7 +5638,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"picocolors@npm:^1.0.0":
+"picocolors@npm:1.0.0, picocolors@npm:^1.0.0":
   version: 1.0.0
   resolution: "picocolors@npm:1.0.0"
   checksum: 20a5b249e331c14479d94ec6817a182fd7a5680debae82705747b2db7ec50009a5f6648d0621c561b0572703f84dbef0858abcbd5856d3c5511426afcb1961f7
@@ -5697,11 +5690,11 @@ __metadata:
   linkType: hard
 
 "prettier@npm:^3.0.0":
-  version: 3.1.1
-  resolution: "prettier@npm:3.1.1"
+  version: 3.2.2
+  resolution: "prettier@npm:3.2.2"
   bin:
     prettier: bin/prettier.cjs
-  checksum: facc944ba20e194ff4db765e830ffbcb642803381f0d2033ed397e79904fa4ccc877dc25ad68f42d36985c01d051c990ca1b905fb83d2d7d65fe69e4386fa1a3
+  checksum: e84d0d2a4ce2b88ee1636904effbdf68b59da63d9f887128f2ed5382206454185432e7c0a9578bc4308bc25d099cfef47fd0b9c211066777854e23e65e34044d
   languageName: node
   linkType: hard