diff --git a/src/main/java/io/vertx/core/file/impl/FileCache.java b/src/main/java/io/vertx/core/file/impl/FileCache.java
index 377c0e9ebcc..6500ab8c6a6 100644
--- a/src/main/java/io/vertx/core/file/impl/FileCache.java
+++ b/src/main/java/io/vertx/core/file/impl/FileCache.java
@@ -216,7 +216,7 @@ void cacheDir(String fileName) throws IOException {
   private void fileNameCheck(File file) throws IOException {
     String fileName = file.getCanonicalPath();
     String cachePath = getCacheDir().getPath();
-    if (fileName.startsWith(cachePath)) {
+    if (file.getCanonicalFile().toPath().startsWith(cachePath)) {
       int cachePathLen = cachePath.length();
       if (fileName.length() == cachePathLen) {
         return;