diff --git a/jsr.json b/jsr.json
index ff3497d..d24bb93 100644
--- a/jsr.json
+++ b/jsr.json
@@ -6,6 +6,7 @@
     "include": [
       "dist/esm/index.js",
       "dist/esm/index.d.ts",
+      "dist/esm/types.ts",
       "README.md",
       "jsr.json",
       "LICENSE"
diff --git a/package.json b/package.json
index 1c4fb25..58ed0d7 100644
--- a/package.json
+++ b/package.json
@@ -42,7 +42,7 @@
   "homepage": "https://github.com/eslint/json#readme",
   "scripts": {
     "build:dedupe-types": "node tools/dedupe-types.js dist/cjs/index.cjs dist/esm/index.js",
-    "build:cts": "node -e \"fs.copyFileSync('dist/esm/index.d.ts', 'dist/cjs/index.d.cts')\"",
+    "build:cts": "node tools/build-cts.js",
     "build": "rollup -c && npm run build:dedupe-types && tsc -p tsconfig.esm.json && npm run build:cts",
     "build:readme": "node tools/update-readme.js",
     "test:jsr": "npx jsr@latest publish --dry-run",
@@ -68,7 +68,6 @@
     "@humanwhocodes/momoa": "^3.3.4"
   },
   "devDependencies": {
-    "@types/eslint": "^8.56.10",
     "c8": "^9.1.0",
     "dedent": "^1.5.3",
     "eslint": "^9.11.1",
diff --git a/rollup.config.js b/rollup.config.js
index 0ec27fb..5b813a8 100644
--- a/rollup.config.js
+++ b/rollup.config.js
@@ -1,3 +1,5 @@
+import copy from "rollup-plugin-copy";
+
 export default {
 	input: "src/index.js",
 	output: [
@@ -11,4 +13,12 @@ export default {
 			banner: '// @ts-self-types="./index.d.ts"',
 		},
 	],
+	plugins: [
+		copy({
+			targets: [
+				{ src: "src/types.ts", dest: "dist/cjs", rename: "types.cts" },
+				{ src: "src/types.ts", dest: "dist/esm" },
+			],
+		}),
+	],
 };
diff --git a/src/languages/json-language.js b/src/languages/json-language.js
index 9948aac..5a719af 100644
--- a/src/languages/json-language.js
+++ b/src/languages/json-language.js
@@ -21,10 +21,8 @@ import { visitorKeys } from "@humanwhocodes/momoa";
 /** @typedef {import("@eslint/core").OkParseResult<DocumentNode>} OkParseResult */
 /** @typedef {import("@eslint/core").ParseResult<DocumentNode>} ParseResult */
 /** @typedef {import("@eslint/core").File} File */
-/**
- * @typedef {Object} JSONLanguageOptions
- * @property {boolean} [allowTrailingCommas] Whether to allow trailing commas.
- */
+/** @typedef {import("../types.ts").IJSONLanguage} IJSONLanguage */
+/** @typedef {import("../types.ts").JSONLanguageOptions} JSONLanguageOptions */
 
 //-----------------------------------------------------------------------------
 // Exports
@@ -32,7 +30,7 @@ import { visitorKeys } from "@humanwhocodes/momoa";
 
 /**
  * JSON Language Object
- * @implements {Language}
+ * @implements {IJSONLanguage}
  */
 export class JSONLanguage {
 	/**
diff --git a/src/languages/json-source-code.js b/src/languages/json-source-code.js
index acec0ec..e512f83 100644
--- a/src/languages/json-source-code.js
+++ b/src/languages/json-source-code.js
@@ -26,11 +26,12 @@ import {
 /** @typedef {import("@eslint/core").SourceLocation} SourceLocation */
 /** @typedef {import("@eslint/core").File} File */
 /** @typedef {import("@eslint/core").TraversalStep} TraversalStep */
-/** @typedef {import("@eslint/core").TextSourceCode} TextSourceCode */
 /** @typedef {import("@eslint/core").VisitTraversalStep} VisitTraversalStep */
 /** @typedef {import("@eslint/core").FileProblem} FileProblem */
 /** @typedef {import("@eslint/core").DirectiveType} DirectiveType */
 /** @typedef {import("@eslint/core").RulesConfig} RulesConfig */
+/** @typedef {import("../types.ts").IJSONSourceCode} IJSONSourceCode */
+/** @typedef {import("../types.ts").JSONSyntaxElement} JSONSyntaxElement */
 
 //-----------------------------------------------------------------------------
 // Helpers
@@ -71,6 +72,7 @@ class JSONTraversalStep extends VisitNodeStep {
 
 /**
  * JSON Source Code Object
+ * @implements {IJSONSourceCode}
  */
 export class JSONSourceCode extends TextSourceCodeBase {
 	/**
@@ -147,7 +149,7 @@ export class JSONSourceCode extends TextSourceCodeBase {
 			);
 		}
 
-		return this.#inlineConfigComments;
+		return this.#inlineConfigComments ?? [];
 	}
 
 	/**
diff --git a/src/rules/no-duplicate-keys.js b/src/rules/no-duplicate-keys.js
index 3499526..e3ac3d6 100644
--- a/src/rules/no-duplicate-keys.js
+++ b/src/rules/no-duplicate-keys.js
@@ -3,13 +3,22 @@
  * @author Nicholas C. Zakas
  */
 
+//-----------------------------------------------------------------------------
+// Type Definitions
+//-----------------------------------------------------------------------------
+
+/** @typedef {"duplicateKey"} NoDuplicateKeysMessageIds */
+/** @typedef {import("../types.ts").JSONRuleDefinition<[], NoDuplicateKeysMessageIds>} NoDuplicateKeysRuleDefinition */
+/** @typedef {import("@humanwhocodes/momoa").MemberNode} MemberNode */
+
 //-----------------------------------------------------------------------------
 // Rule Definition
 //-----------------------------------------------------------------------------
 
+/** @type {NoDuplicateKeysRuleDefinition} */
 export default {
 	meta: {
-		type: /** @type {const} */ ("problem"),
+		type: "problem",
 
 		docs: {
 			description: "Disallow duplicate keys in JSON objects",
@@ -21,7 +30,10 @@ export default {
 	},
 
 	create(context) {
+		/** @type {Array<Map<string, MemberNode>|undefined>} */
 		const objectKeys = [];
+
+		/** @type {Map<string, MemberNode>|undefined} */
 		let keys;
 
 		return {
diff --git a/src/rules/no-empty-keys.js b/src/rules/no-empty-keys.js
index 3fedc4f..73983cc 100644
--- a/src/rules/no-empty-keys.js
+++ b/src/rules/no-empty-keys.js
@@ -3,9 +3,21 @@
  * @author Nicholas C. Zakas
  */
 
+//-----------------------------------------------------------------------------
+// Type Definitions
+//-----------------------------------------------------------------------------
+
+/** @typedef {"emptyKey"} NoEmptyKeysMessageIds */
+/** @typedef {import("../types.ts").JSONRuleDefinition<[], NoEmptyKeysMessageIds>} NoEmptyKeysRuleDefinition */
+
+//-----------------------------------------------------------------------------
+// Rule Definition
+//-----------------------------------------------------------------------------
+
+/** @type {NoEmptyKeysRuleDefinition} */
 export default {
 	meta: {
-		type: /** @type {const} */ ("problem"),
+		type: "problem",
 
 		docs: {
 			description: "Disallow empty keys in JSON objects",
diff --git a/src/rules/no-unsafe-values.js b/src/rules/no-unsafe-values.js
index ed29a48..6249e23 100644
--- a/src/rules/no-unsafe-values.js
+++ b/src/rules/no-unsafe-values.js
@@ -3,15 +3,36 @@
  * @author Bradley Meck Farias
  */
 
-// RFC 8259's `number` production, as a regex.  Capture the integer part
-// and the fractional part.
+//-----------------------------------------------------------------------------
+// Type Definitions
+//-----------------------------------------------------------------------------
+
+/** @typedef {"unsafeNumber"|"unsafeInteger"|"unsafeZero"|"subnormal"|"loneSurrogate"} NoUnsafeValuesMessageIds */
+/** @typedef {import("../types.ts").JSONRuleDefinition<[], NoUnsafeValuesMessageIds>} NoUnsafeValuesRuleDefinition */
+
+//-----------------------------------------------------------------------------
+// Helpers
+//-----------------------------------------------------------------------------
+
+/*
+ * This rule is based on the JSON grammar from RFC 8259, section 6.
+ * https://tools.ietf.org/html/rfc8259#section-6
+ *
+ * We separately capture the integer and fractional parts of a number, so that
+ * we can check for unsafe numbers that will evaluate to Infinity.
+ */
 const NUMBER =
 	/^-?(?<int>0|([1-9][0-9]*))(?:\.(?<frac>[0-9]+))?(?:[eE][+-]?[0-9]+)?$/u;
 const NON_ZERO = /[1-9]/u;
 
+//-----------------------------------------------------------------------------
+// Rule Definition
+//-----------------------------------------------------------------------------
+
+/** @type {NoUnsafeValuesRuleDefinition} */
 export default {
 	meta: {
-		type: /** @type {const} */ ("problem"),
+		type: "problem",
 
 		docs: {
 			description: "Disallow JSON values that are unsafe for interchange",
@@ -85,7 +106,9 @@ export default {
 								loc: node.loc,
 								messageId: "subnormal",
 								// Value included so that it's seen in scientific notation
-								data: node,
+								data: {
+									value,
+								},
 							});
 						}
 					}
diff --git a/src/types.ts b/src/types.ts
new file mode 100644
index 0000000..9c08e8b
--- /dev/null
+++ b/src/types.ts
@@ -0,0 +1,128 @@
+/**
+ * @fileoverview Additional types for this package.
+ * @author Nicholas C. Zakas
+ */
+
+//------------------------------------------------------------------------------
+// Imports
+//------------------------------------------------------------------------------
+
+import type {
+	RuleVisitor,
+	TextSourceCode,
+	Language,
+	LanguageOptions,
+	RuleDefinition,
+} from "@eslint/core";
+import {
+	DocumentNode,
+	MemberNode,
+	ElementNode,
+	ObjectNode,
+	ArrayNode,
+	StringNode,
+	NullNode,
+	NumberNode,
+	BooleanNode,
+	NaNNode,
+	InfinityNode,
+	IdentifierNode,
+	AnyNode,
+	Token,
+} from "@humanwhocodes/momoa";
+
+//------------------------------------------------------------------------------
+// Types
+//------------------------------------------------------------------------------
+
+type ValueNodeParent = DocumentNode | MemberNode | ElementNode;
+
+/**
+ * A JSON syntax element, including nodes and tokens.
+ */
+export type JSONSyntaxElement = Token | AnyNode;
+
+/**
+ * Language options provided for JSON files.
+ */
+export interface JSONLanguageOptions extends LanguageOptions {
+	/**
+	 * Whether to allow trailing commas. Only valid in JSONC.
+	 */
+	allowTrailingCommas?: boolean;
+}
+
+/**
+ * The visitor format returned from rules in this package.
+ */
+export interface JSONRuleVisitor extends RuleVisitor {
+	Document?(node: DocumentNode): void;
+	Member?(node: MemberNode, parent?: ObjectNode): void;
+	Element?(node: ElementNode, parent?: ArrayNode): void;
+	Object?(node: ObjectNode, parent?: ValueNodeParent): void;
+	Array?(node: ArrayNode, parent?: ValueNodeParent): void;
+	String?(node: StringNode, parent?: ValueNodeParent): void;
+	Null?(node: NullNode, parent?: ValueNodeParent): void;
+	Number?(node: NumberNode, parent?: ValueNodeParent): void;
+	Boolean?(node: BooleanNode, parent?: ValueNodeParent): void;
+	NaN?(node: NaNNode, parent?: ValueNodeParent): void;
+	Infinity?(node: InfinityNode, parent?: ValueNodeParent): void;
+	Identifier?(node: IdentifierNode, parent?: ValueNodeParent): void;
+
+	"Document:exit"?(node: DocumentNode): void;
+	"Member:exit"?(node: MemberNode, parent?: ObjectNode): void;
+	"Element:exit"?(node: ElementNode, parent?: ArrayNode): void;
+	"Object:exit"?(node: ObjectNode, parent?: ValueNodeParent): void;
+	"Array:exit"?(node: ArrayNode, parent?: ValueNodeParent): void;
+	"String:exit"?(node: StringNode, parent?: ValueNodeParent): void;
+	"Null:exit"?(node: NullNode, parent?: ValueNodeParent): void;
+	"Number:exit"?(node: NumberNode, parent?: ValueNodeParent): void;
+	"Boolean:exit"?(node: BooleanNode, parent?: ValueNodeParent): void;
+	"NaN:exit"?(node: NaNNode, parent?: ValueNodeParent): void;
+	"Infinity:exit"?(node: InfinityNode, parent?: ValueNodeParent): void;
+	"Identifier:exit"?(node: IdentifierNode, parent?: ValueNodeParent): void;
+}
+
+/**
+ * The `SourceCode` implementation for JSON files.
+ */
+export interface IJSONSourceCode
+	extends TextSourceCode<{
+		LangOptions: JSONLanguageOptions;
+		RootNode: DocumentNode;
+		SyntaxElementWithLoc: JSONSyntaxElement;
+		ConfigNode: Token;
+	}> {
+	/**
+	 * Get the text of a syntax element.
+	 * @param syntaxElement The syntax element to get the text of.
+	 * @param beforeCount The number of characters to include before the syntax element.
+	 * @param afterCount The number of characters to include after the syntax element.
+	 * @returns The text of the syntax element.
+	 */
+	getText(
+		syntaxElement: JSONSyntaxElement,
+		beforeCount?: number,
+		afterCount?: number,
+	): string;
+}
+
+export type IJSONLanguage = Language<{
+	LangOptions: JSONLanguageOptions;
+	Code: IJSONSourceCode;
+	RootNode: DocumentNode;
+	Node: AnyNode;
+}>;
+
+export type JSONRuleDefinition<
+	JSONRuleOptions extends unknown[],
+	JSONRuleMessageIds extends string = "",
+> = RuleDefinition<{
+	LangOptions: JSONLanguageOptions;
+	Code: IJSONSourceCode;
+	RuleOptions: JSONRuleOptions;
+	Visitor: JSONRuleVisitor;
+	Node: AnyNode;
+	MessageIds: JSONRuleMessageIds;
+	ExtRuleDocs: {};
+}>;
diff --git a/tests/rules/no-unsafe-values.test.js b/tests/rules/no-unsafe-values.test.js
index 7e8234b..4a75c85 100644
--- a/tests/rules/no-unsafe-values.test.js
+++ b/tests/rules/no-unsafe-values.test.js
@@ -251,7 +251,7 @@ ruleTester.run("no-unsafe-values", rule, {
 				{
 					messageId: "subnormal",
 					data: {
-						value: "2.225073858507201e-308",
+						value: "2.2250738585072009e-308",
 					},
 					line: 1,
 					column: 1,
@@ -266,7 +266,7 @@ ruleTester.run("no-unsafe-values", rule, {
 				{
 					messageId: "subnormal",
 					data: {
-						value: "-2.225073858507201e-308",
+						value: "-2.2250738585072009e-308",
 					},
 					line: 1,
 					column: 1,
diff --git a/tests/types/types.test.ts b/tests/types/types.test.ts
index a9f5374..6e6edd0 100644
--- a/tests/types/types.test.ts
+++ b/tests/types/types.test.ts
@@ -1,7 +1,7 @@
 import json from "@eslint/json";
-import { ESLint } from "eslint";
+// import { ESLint } from "eslint";
 
-json satisfies ESLint.Plugin;
+// json satisfies ESLint.Plugin;
 json.meta.name satisfies string;
 json.meta.version satisfies string;
 
diff --git a/tools/build-cts.js b/tools/build-cts.js
new file mode 100644
index 0000000..ade7ae1
--- /dev/null
+++ b/tools/build-cts.js
@@ -0,0 +1,16 @@
+/**
+ * @fileoverview Rewrites import expressions for CommonJS compatibility.
+ * This script creates "dist/cjs/index.d.cts" from "dist/esm/index.d.ts" by modifying imports
+ * from `"./types.ts"` to `"./types.cts"`.
+ *
+ * @author Francesco Trotta
+ */
+
+import { readFile, writeFile } from "node:fs/promises";
+
+const oldSourceText = await readFile("dist/esm/index.d.ts", "utf-8");
+const newSourceText = oldSourceText.replaceAll(
+	'import("./types.ts")',
+	'import("./types.cts")',
+);
+await writeFile("dist/cjs/index.d.cts", newSourceText);
diff --git a/tools/dedupe-types.js b/tools/dedupe-types.js
index ce8b16d..b4a4ada 100644
--- a/tools/dedupe-types.js
+++ b/tools/dedupe-types.js
@@ -39,5 +39,10 @@ files.forEach(filePath => {
 		return true;
 	});
 
-	fs.writeFileSync(filePath, remainingLines.join("\n"), "utf8");
+	// replace references to ../types.ts with ./types.ts
+	const text = remainingLines
+		.join("\n")
+		.replace(/\.\.\/types\.ts/gu, "./types.ts");
+
+	fs.writeFileSync(filePath, text, "utf8");
 });
diff --git a/tsconfig.json b/tsconfig.json
index 3fa504c..2e82117 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -6,8 +6,9 @@
     "allowJs": true,
     "checkJs": true,
     "outDir": "dist/esm",
-    "target": "ES2022",
+    "target": "ESNext",
     "moduleResolution": "NodeNext",
-    "module": "NodeNext"
+    "module": "NodeNext",
+    "allowImportingTsExtensions": true
   }
 }