diff --git a/src/libsync/vfs/suffix/vfs_suffix.cpp b/src/libsync/vfs/suffix/vfs_suffix.cpp
index aac43ea81..9860c24b2 100644
--- a/src/libsync/vfs/suffix/vfs_suffix.cpp
+++ b/src/libsync/vfs/suffix/vfs_suffix.cpp
@@ -63,6 +63,11 @@ void VfsSuffix::createPlaceholder(const SyncFileItem &item)
 {
     // The concrete shape of the placeholder is also used in isDehydratedPlaceholder() below
     QString fn = _setupParams.filesystemPath + item._file;
+    if (!fn.endsWith(fileSuffix())) {
+        ASSERT(false, "vfs file isn't ending with suffix");
+        return;
+    }
+
     QFile file(fn);
     file.open(QFile::ReadWrite | QFile::Truncate);
     file.write(" ");