diff --git a/src/conversion/katakana.ts b/src/conversion/katakana.ts
index aaf9398..739a3bb 100644
--- a/src/conversion/katakana.ts
+++ b/src/conversion/katakana.ts
@@ -153,7 +153,7 @@ export interface KanaConversionOptions {
 }
 
 /** Gemination normalization, always applied (not user-configurable). */
-const GEMINATION_TABLE = {
+export const GEMINATION_TABLE = {
 	ㇷ゚パ: "ッパ",
 	ㇷ゚ピ: "ッピ",
 	ㇷ゚ペ: "ッペ",
diff --git a/test/index.test.ts b/test/index.test.ts
index e4a1124..4625241 100644
--- a/test/index.test.ts
+++ b/test/index.test.ts
@@ -1,4 +1,5 @@
 import { expect, test } from "bun:test";
+import { GEMINATION_TABLE } from "../src/conversion/katakana";
 import {
 	convertCyrlToHang,
 	convertCyrlToKana,
@@ -27,6 +28,14 @@ function removeYiWu(str: string) {
 	return str.replace(/yi/, "i").replace(/wu/, "u");
 }
 
+function normalizeGemination(kana: string) {
+	let normalized = kana;
+	for (const [variant, replacement] of Object.entries(GEMINATION_TABLE)) {
+		normalized = normalized.replaceAll(variant, replacement);
+	}
+	return normalized;
+}
+
 test("Script Detection", () => {
 	expect(detect("aynu")).toBe("Latn");
 	expect(detect("アイヌ")).toBe("Kana");
@@ -47,7 +56,7 @@ test("Script Conversion (Latn -> Kana)", () => {
 	for (const testCase of TEST_CASES) {
 		const { latn, kana } = testCase;
 		const converted = convertLatnToKana(latn);
-		const expected = kana.replace("ㇰカ", "ッカ");
+		const expected = normalizeGemination(kana);
 		if (converted !== expected) {
 			console.log(`"${latn}" -> "${converted}" (expecting "${expected}")`);
 		}
@@ -61,7 +70,7 @@ test("Script Conversion (Latn -> Kana) with options", () => {
 			testCase as { variants?: { options: object; kana: string }[] }
 		).variants ?? []) {
 			const converted = convertLatnToKana(testCase.latn, variant.options);
-			const expected = variant.kana.replace("ㇰカ", "ッカ");
+			const expected = normalizeGemination(variant.kana);
 			if (converted !== expected) {
 				console.log(
 					`"${testCase.latn}" ${JSON.stringify(variant.options)} -> "${converted}" (expecting "${expected}")`,
@@ -141,7 +150,7 @@ test("Script Conversion (Cyrl -> Kana)", () => {
 	for (const testCase of TEST_CASES) {
 		const { kana, cyrl } = testCase;
 		const converted = convertCyrlToKana(cyrl);
-		const expected = kana.replace("ㇰカ", "ッカ");
+		const expected = normalizeGemination(kana);
 		if (converted !== expected) {
 			console.log(`"${cyrl}" -> "${converted}" (expecting "${kana}")`);
 		}
@@ -182,7 +191,7 @@ test("Script Conversion (Hang -> Kana)", () => {
 	for (const testCase of TEST_CASES) {
 		const { kana, hang } = testCase;
 		const converted = convertHangToKana(hang);
-		const expected = kana.replace("ㇰカ", "ッカ");
+		const expected = normalizeGemination(kana);
 		if (converted !== expected) {
 			console.log(`"${hang}" -> "${converted}" (expecting "${expected}")`);
 		}
@@ -191,7 +200,7 @@ test("Script Conversion (Hang -> Kana)", () => {
 
 	for (const testCase of ROBUSTNESS.filter((t) => t.from === "Hang")) {
 		const { Hang, Kana } = testCase;
-		expect(convertHangToKana(Hang)).toBe(Kana.replace("ㇰカ", "ッカ"));
+		expect(convertHangToKana(Hang)).toBe(normalizeGemination(Kana));
 	}
 });