diff --git a/sources/COPERNICUS.cpp b/sources/COPERNICUS.cpp
index 82f921b..48747a7 100644
--- a/sources/COPERNICUS.cpp
+++ b/sources/COPERNICUS.cpp
@@ -129,6 +129,9 @@ Error COPERNICUSData::Mirror(const CLArgs& args) const
   dsets = dlist.Value();
  }
 
+ michlib::RegExpSimple filter((args.contains("filter") ? args.at("filter") : ".*").Buf());
+ if(filter.Compile() != 0) return Error(pref, MString("Can't compile regular expression ") + filter.RegStr());
+
  CURLRAII chandle;
  for(const auto& dset: dsets)
  {
@@ -154,20 +157,34 @@ Error COPERNICUSData::Mirror(const CLArgs& args) const
    while(rpos != rfiles.size() || lpos != lfiles.size())
    {
     if(rpos == rfiles.size())
-     while(lpos != lfiles.size()) rem.push_back(lpos++);
+     while(lpos != lfiles.size())
+     {
+      if(filter.Match(lfiles[lpos].name.Buf())) rem.push_back(lpos);
+      lpos++;
+     }
     if(lpos == lfiles.size())
-     while(rpos != rfiles.size()) down.push_back(rpos++);
+     while(rpos != rfiles.size())
+     {
+      if(filter.Match(rfiles[rpos].name.Buf())) down.push_back(rpos);
+      rpos++;
+     }
     if(rpos == rfiles.size() || lpos == lfiles.size()) continue;
 
     if(rfiles[rpos].name < lfiles[lpos].name)
-     down.push_back(rpos++);
+    {
+     if(filter.Match(rfiles[rpos].name.Buf())) down.push_back(rpos);
+     rpos++;
+    }
     else if(lfiles[lpos].name < rfiles[rpos].name)
-     rem.push_back(lpos++);
+    {
+     if(filter.Match(lfiles[lpos].name.Buf())) rem.push_back(lpos);
+     lpos++;
+    }
     else
     {
      auto delta = rfiles[rpos].mtime.Epoch() - lfiles[lpos].mtime.Epoch();
      if(delta < 0) delta = -delta;
-     if(delta > 0 || rfiles[rpos].size != lfiles[lpos].size) upd.emplace_back(rpos, lpos);
+     if((delta > 0 || rfiles[rpos].size != lfiles[lpos].size) && filter.Match(lfiles[lpos].name.Buf())) upd.emplace_back(rpos, lpos);
      lpos++;
      rpos++;
     }