diff --git a/scripts/build.ts b/scripts/build.ts
index ca73b55d..ab9c1269 100644
--- a/scripts/build.ts
+++ b/scripts/build.ts
@@ -341,19 +341,25 @@ class Builder {
 			]);
 		});
 
-		// TODO: fix onigasm dep
-		// # onigasm 2.2.2 has a bug that makes it broken for PHP files so use 2.2.1.
-		// # https://github.com/NeekSandhu/onigasm/issues/17
-		// function fix-onigasm() {
-		// 	local onigasmPath="${buildPath}/node_modules/onigasm-umd"
-		// 	rm -rf "${onigasmPath}"
-		// 	git clone "https://github.com/alexandrudima/onigasm-umd" "${onigasmPath}"
-		// 	cd "${onigasmPath}" && yarn && yarn add --dev onigasm@2.2.1 && yarn package
-		// 	mkdir "${onigasmPath}-temp"
-		// 	mv "${onigasmPath}/"{release,LICENSE} "${onigasmPath}-temp"
-		// 	rm -rf "${onigasmPath}"
-		// 	mv "${onigasmPath}-temp" "${onigasmPath}"
-		// }
+		// onigasm 2.2.2 has a bug that makes it broken for PHP files so use 2.2.1.
+		// https://github.com/NeekSandhu/onigasm/issues/17
+		await this.task("Applying onigasm PHP fix", async () => {
+			const onigasmPath = path.join(finalBuildPath, "node_modules/onigasm-umd");
+			const onigasmTmpPath = `${onigasmPath}-temp`;
+			await Promise.all([
+				fs.remove(onigasmPath),
+				fs.mkdir(onigasmTmpPath),
+			]);
+			await util.promisify(cp.exec)(`git clone "https://github.com/alexandrudima/onigasm-umd" "${onigasmPath}"`);
+			await util.promisify(cp.exec)("yarn", { cwd: onigasmPath });
+			await util.promisify(cp.exec)("yarn add --dev onigasm@2.2.1", { cwd: onigasmPath });
+			await util.promisify(cp.exec)("yarn package", { cwd: onigasmPath });
+			await Promise.all(["release", "LICENSE", "package.json"].map((fileName) => {
+				return fs.copy(path.join(onigasmPath, fileName), path.join(onigasmTmpPath, fileName));
+			}));
+			await fs.remove(onigasmPath);
+			await fs.move(onigasmTmpPath, onigasmPath);
+		});
 
 		this.log(`Final build: ${finalBuildPath}`);
 	}