diff --git a/Rdutil.cc b/Rdutil.cc
index f098d2c..6c552f0 100644
--- a/Rdutil.cc
+++ b/Rdutil.cc
@@ -61,7 +61,7 @@ Rdutil::printtofile(const std::string& filename) const
 // returns how many times the function was invoked.
 template<typename Function>
 std::size_t
-applyactiononfile(std::vector<Fileinfo>& m_list, Function f)
+applyactiononfile(std::vector<Fileinfo>& m_list, bool m_protectSameTree, Function f)
 {
 
   const auto first = m_list.begin();
@@ -79,9 +79,12 @@ applyactiononfile(std::vector<Fileinfo>& m_list, Function f)
                "original file should have positive identity");
       } break;
 
-      case Fileinfo::duptype::DUPTYPE_OUTSIDE_TREE:
+      case Fileinfo::duptype::DUPTYPE_WITHIN_SAME_TREE:
+        if (m_protectSameTree) {
+          break;
+        }
         // intentional fallthrough
-      case Fileinfo::duptype::DUPTYPE_WITHIN_SAME_TREE: {
+      case Fileinfo::duptype::DUPTYPE_OUTSIDE_TREE: {
         assert(original != last);
         // double check that "it" shall be ~linked to "src"
         assert(it->getidentity() == -original->getidentity() &&
@@ -140,11 +143,11 @@ Rdutil::deleteduplicates(bool dryrun) const
   if (dryrun) {
     const bool outputBname = false;
     dryrun_helper<outputBname> obj("delete ");
-    auto ret = applyactiononfile(m_list, obj);
+    auto ret = applyactiononfile(m_list, m_protectSameTree, obj);
     std::cout.flush();
     return ret;
   } else {
-    return applyactiononfile(m_list, &Fileinfo::static_deletefile);
+    return applyactiononfile(m_list, m_protectSameTree, &Fileinfo::static_deletefile);
   }
 }
 
@@ -154,11 +157,11 @@ Rdutil::makesymlinks(bool dryrun) const
   if (dryrun) {
     const bool outputBname = true;
     dryrun_helper<outputBname> obj("symlink ", " to ");
-    auto ret = applyactiononfile(m_list, obj);
+    auto ret = applyactiononfile(m_list, m_protectSameTree, obj);
     std::cout.flush();
     return ret;
   } else {
-    return applyactiononfile(m_list, &Fileinfo::static_makesymlink);
+    return applyactiononfile(m_list, m_protectSameTree, &Fileinfo::static_makesymlink);
   }
 }
 
@@ -168,11 +171,11 @@ Rdutil::makehardlinks(bool dryrun) const
   if (dryrun) {
     const bool outputBname = true;
     dryrun_helper<outputBname> obj("hardlink ", " to ");
-    const auto ret = applyactiononfile(m_list, obj);
+    const auto ret = applyactiononfile(m_list, m_protectSameTree, obj);
     std::cout.flush();
     return ret;
   } else
-    return applyactiononfile(m_list, &Fileinfo::static_makehardlink);
+    return applyactiononfile(m_list, m_protectSameTree, &Fileinfo::static_makehardlink);
 }
 
 // mark files with a unique number
diff --git a/Rdutil.hh b/Rdutil.hh
index b39e2e9..d4967b6 100644
--- a/Rdutil.hh
+++ b/Rdutil.hh
@@ -16,8 +16,8 @@
 class Rdutil
 {
 public:
-  explicit Rdutil(std::vector<Fileinfo>& list)
-    : m_list(list){};
+  explicit Rdutil(std::vector<Fileinfo>& list, bool protectSameTree)
+    : m_list(list), m_protectSameTree(protectSameTree) {};
 
   /**
    * print file names to a file, with extra information.
@@ -121,6 +121,7 @@ public:
 
 private:
   std::vector<Fileinfo>& m_list;
+  bool m_protectSameTree;
 };
 
 #endif
diff --git a/rdfind.cc b/rdfind.cc
index facdda7..4c66589 100644
--- a/rdfind.cc
+++ b/rdfind.cc
@@ -72,6 +72,8 @@ usage()
     << " -outputname  name  sets the results file name to \"name\" "
        "(default results.txt)\n"
     << " -deleteduplicates  true |(false) delete duplicate files\n"
+    << " -protectsametree   true |(false) do not touch duplicates found in "
+       "the same tree as the original\n"
     << " -sleep              Xms          sleep for X milliseconds between "
        "file reads.\n"
     << "                                  Default is 0. Only a few values\n"
@@ -99,6 +101,7 @@ struct Options
   Fileinfo::filesizetype maximumfilesize =
     0; // if nonzero, files this size or larger are ignored
   bool deleteduplicates = false;      // delete duplicate files
+  bool protectsametree = false;       // do not touch duplicates in same tree
   bool followsymlinks = false;        // follow symlinks
   bool dryrun = false;                // only dryrun, dont destroy anything
   bool remove_identical_inode = true; // remove files with identical inodes
@@ -156,6 +159,8 @@ parseOptions(Parser& parser)
       o.maximumfilesize = maxsize;
     } else if (parser.try_parse_bool("-deleteduplicates")) {
       o.deleteduplicates = parser.get_parsed_bool();
+    } else if (parser.try_parse_bool("-protectsametree")) {
+      o.protectsametree = parser.get_parsed_bool();
     } else if (parser.try_parse_bool("-followsymlinks")) {
       o.followsymlinks = parser.get_parsed_bool();
     } else if (parser.try_parse_bool("-dryrun")) {
@@ -286,7 +291,7 @@ main(int narg, const char* argv[])
   const std::string dryruntext(o.dryrun ? "(DRYRUN MODE) " : "");
 
   // an object to do sorting and duplicate finding
-  Rdutil gswd(filelist);
+  Rdutil gswd(filelist, o.protectsametree);
 
   // an object to traverse the directory structure
   Dirlist dirlist(o.followsymlinks);