diff --git a/dist/index.js b/dist/index.js
index 75cbe17ea..18b3c42a0 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -1121,7 +1121,7 @@ exports.fetch = fetch;
 async function parseVersion(version) {
     const manifest = 'https://dl.bintray.com/shivammathur/php/php-versions.json';
     switch (true) {
-        case /latest|\d.x/.test(version):
+        case /^(latest|\d+\.x)$/.test(version):
             return JSON.parse(await fetch(manifest))[version];
         default:
             switch (true) {
diff --git a/src/utils.ts b/src/utils.ts
index cb3af9c09..4e42f4a80 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -69,7 +69,7 @@ export async function fetch(url: string): Promise<string> {
 export async function parseVersion(version: string): Promise<string> {
   const manifest = 'https://dl.bintray.com/shivammathur/php/php-versions.json';
   switch (true) {
-    case /latest|\d.x/.test(version):
+    case /^(latest|\d+\.x)$/.test(version):
       return JSON.parse(await fetch(manifest))[version];
     default:
       switch (true) {