diff --git a/src/namspace.c b/src/namspace.c
index 6bd779d..25fd4b0 100644
--- a/src/namspace.c
+++ b/src/namspace.c
@@ -912,10 +912,32 @@ static int build_dos_name(DIR_BASE_ENTRY *e, uint8 *fname, int size_fname)
 {
   char *parent_unix;
   int result;
+  N_NW_PATH parent_path;
+  int plen;
 
   if (!e || !fname || size_fname < 2) return(0);
 
-  parent_unix = alloc_nwpath2unix(&(e->nwpath), 1|2);
+  /*
+   * e->nwpath.path contains the full entry path and e->nwpath.fn points to
+   * the last component inside that buffer.  alloc_nwpath2unix(..., 1|2)
+   * only gives the parent if fn is behind path.  For entries directly in the
+   * volume root fn == path, so the old code accidentally used the entry
+   * itself as parent.  That made collision checks local to each directory and
+   * both "long directory name one" and "long directory name two" became
+   * LONG_DIR.
+   */
+  memcpy(&parent_path, &(e->nwpath), sizeof(parent_path));
+  if (e->nwpath.fn && e->nwpath.fn > e->nwpath.path) {
+    plen = (int)(e->nwpath.fn - e->nwpath.path);
+    if (plen > 0 && e->nwpath.path[plen-1] == '/') --plen;
+    memcpy(parent_path.path, e->nwpath.path, plen);
+    parent_path.path[plen] = '\0';
+  } else {
+    parent_path.path[0] = '\0';
+  }
+  parent_path.fn = parent_path.path + strlen((char*)parent_path.path);
+
+  parent_unix = alloc_nwpath2unix(&parent_path, 2);
   result = build_dos_83_alias(get_volume_options(e->nwpath.volume),
                               (uint8*)parent_unix,
                               e->nwpath.fn,