diff --git a/l4d2web/l4d2web/static/js/files-overlay/uploads.js b/l4d2web/l4d2web/static/js/files-overlay/uploads.js
index f0f78e6..ce03fac 100644
--- a/l4d2web/l4d2web/static/js/files-overlay/uploads.js
+++ b/l4d2web/l4d2web/static/js/files-overlay/uploads.js
@@ -37,11 +37,29 @@
   const uploadsList = uploadsPanel?.querySelector(".files-uploads-list");
   const uploadsClearBtn = uploadsPanel?.querySelector(".files-uploads-clear");
 
-  // Attach a path-collision suffix: foo.txt → foo (1).txt
+  // Attach a path-collision suffix: foo.txt → foo (1).txt.
+  // Recognizes common compressed-tar double-extensions so
+  // foo.tar.gz → foo (1).tar.gz, not foo.tar (1).gz.
+  const DOUBLE_EXTS = [
+    ".tar.gz", ".tar.bz2", ".tar.xz", ".tar.zst", ".tar.lz", ".tar.lzma",
+  ];
   function withCollisionSuffix(path) {
-    const dot = path.lastIndexOf(".");
     const slash = path.lastIndexOf("/");
-    if (dot > slash + 0 && dot > -1) {
+    const stemStart = slash + 1;
+    const basename = path.slice(stemStart);
+    const lower = basename.toLowerCase();
+    for (const ext of DOUBLE_EXTS) {
+      if (lower.endsWith(ext) && basename.length > ext.length) {
+        const cut = stemStart + basename.length - ext.length;
+        return path.slice(0, cut) + " (1)" + path.slice(cut);
+      }
+    }
+    // Single extension (or none). A dot must appear after the last
+    // slash to count as an extension — preserves the legacy behavior
+    // where a leading-dot basename like ".hidden" gets the suffix at
+    // the end rather than at position 0.
+    const dot = path.lastIndexOf(".");
+    if (dot > slash && dot > -1) {
       return path.slice(0, dot) + " (1)" + path.slice(dot);
     }
     return path + " (1)";