diff --git a/package.json b/package.json
index 993b2ff8..7edd672f 100644
--- a/package.json
+++ b/package.json
@@ -34,7 +34,10 @@
 		"@sveltejs/package": "^2.5.7",
 		"@sveltejs/vite-plugin-svelte": "^7.2.0",
 		"@types/d3": "^7.4.3",
+		"@types/d3-hierarchy": "^3.1.7",
 		"@types/d3-sankey": "^0.12.4",
+		"@types/d3-scale": "^4.0.9",
+		"@types/d3-shape": "^3.1.8",
 		"@types/markdown-it": "^14.1.2",
 		"@types/node": "^26.1.1",
 		"d3-collection": "^1.0.7",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index bd9a2d09..813a2102 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -42,9 +42,18 @@ importers:
       '@types/d3':
         specifier: ^7.4.3
         version: 7.4.3
+      '@types/d3-hierarchy':
+        specifier: ^3.1.7
+        version: 3.1.7
       '@types/d3-sankey':
         specifier: ^0.12.4
         version: 0.12.5
+      '@types/d3-scale':
+        specifier: ^4.0.9
+        version: 4.0.9
+      '@types/d3-shape':
+        specifier: ^3.1.8
+        version: 3.1.8
       '@types/markdown-it':
         specifier: ^14.1.2
         version: 14.1.2
diff --git a/src/_components/CirclePack.html.svelte b/src/_components/CirclePack.html.svelte
index 82836567..9b01d7d1 100644
--- a/src/_components/CirclePack.html.svelte
+++ b/src/_components/CirclePack.html.svelte
@@ -12,7 +12,7 @@
 
 	const { width, height, data } = getContext('LayerCake');
 
-	/** @typedef {import('d3-hierarchy').HierarchyNode} HierarchyNode */
+	/** @typedef {import('d3-hierarchy').HierarchyNode<any>} HierarchyNode */
 
 	/**
 	 * @typedef {Object} Props
diff --git a/src/_components/Sankey.svelte b/src/_components/Sankey.svelte
index cc281a69..9e3ee6fd 100644
--- a/src/_components/Sankey.svelte
+++ b/src/_components/Sankey.svelte
@@ -17,11 +17,11 @@
 	 * )} SankeyAlignment
 	 */
 
-	/** @typedef {import('d3-sankey').SankeyGraph} SankeyGraph */
+	/** @typedef {import('d3-sankey').SankeyGraph<any, any>} SankeyGraph */
 
-	/** @typedef {import('d3-sankey').SankeyNodeMinimal} SankeyNodeMinimal */
+	/** @typedef {import('d3-sankey').SankeyNodeMinimal<any, any>} SankeyNodeMinimal */
 
-	/** @typedef {import('d3-sankey').SankeyLinkMinimal} SankeyLink */
+	/** @typedef {import('d3-sankey').SankeyLinkMinimal<any, any>} SankeyLink */
 
 	/**
 	 * @typedef {((a: SankeyLink, b: SankeyLink) => (number | undefined | null))} LinkSortFunction
@@ -35,7 +35,7 @@
 	 * @property {number} [nodeWidth=5] - The width of each node, in pixels, passed to [`sankey.nodeWidth`](https://github.com/d3/d3-sankey#sankey_nodeWidth).
 	 * @property {number} [nodePadding=10] - The padding between nodes, passed to [`sankey.nodePadding`](https://github.com/d3/d3-sankey#sankey_nodePadding).
 	 * @property {LinkSortFunction|undefined} [linkSort] - How to sort the links, passed to [`sankey.linkSort`](https://github.com/d3/d3-sankey#sankey_linkSort).
-	 * @property {(SankeyNodeMinimal) => number | string} [nodeId=(d) => d.id] - The ID field accessor, passed to [`sankey.nodeId`](https://github.com/d3/d3-sankey#sankey_nodeId).
+	 * @property {(d: SankeyNodeMinimal) => number | string} [nodeId=(d) => d.id] - The ID field accessor, passed to [`sankey.nodeId`](https://github.com/d3/d3-sankey#sankey_nodeId).
 	 * @property {SankeyAlignment} [nodeAlign=Sankey.sankeyLeft] - An alignment function to position the Sankey blocks. See the [d3-sankey documentation](https://github.com/d3/d3-sankey#alignments) for more.
 	 */
 
diff --git a/test/e2e/component-properties-table.spec.js-snapshots/Property-table-content-for-components-Sankey-svelte-1.aria.yml b/test/e2e/component-properties-table.spec.js-snapshots/Property-table-content-for-components-Sankey-svelte-1.aria.yml
index 121fc018..a7777285 100644
--- a/test/e2e/component-properties-table.spec.js-snapshots/Property-table-content-for-components-Sankey-svelte-1.aria.yml
+++ b/test/e2e/component-properties-table.spec.js-snapshots/Property-table-content-for-components-Sankey-svelte-1.aria.yml
@@ -73,11 +73,11 @@
           - /url: https://github.com/d3/d3-sankey#sankey_linkSort
           - code: sankey.linkSort
         - text: ""
-    - row "nodeId ((SankeyNodeMinimal) => number | string) d => d.id no The ID field accessor, passed to sankey.nodeId.":
-      - cell "nodeId ((SankeyNodeMinimal) => number | string)":
+    - 'row "nodeId ((d: SankeyNodeMinimal) => number | string) d => d.id no The ID field accessor, passed to sankey.nodeId."':
+      - 'cell "nodeId ((d: SankeyNodeMinimal) => number | string)"':
         - strong: nodeId
         - text: ""
-        - code: (SankeyNodeMinimal) => number
+        - code: "(d: SankeyNodeMinimal) => number"
         - text: ""
         - code: string
         - text: ""