diff --git a/rtgui/thumbbrowserbase.cc b/rtgui/thumbbrowserbase.cc
index ed6366266..3536cc9b7 100644
--- a/rtgui/thumbbrowserbase.cc
+++ b/rtgui/thumbbrowserbase.cc
@@ -98,81 +98,85 @@ void ThumbBrowserBase::scrollPage (int direction)
     }
 }
 
-void ThumbBrowserBase::selectSingle (ThumbBrowserEntryBase* fileDescr)
+namespace
 {
-    for (size_t i = 0; i < selected.size(); i++) {
-        selected[i]->selected = false;
-    }
+
+typedef std::vector<ThumbBrowserEntryBase*> ThumbVector;
+typedef ThumbVector::iterator ThumbIterator;
+
+inline void clearSelection (ThumbVector& selected)
+{
+    for (ThumbIterator thumb = selected.begin (); thumb != selected.end (); ++thumb)
+        (*thumb)->selected = false;
 
     selected.clear ();
+}
 
-    if (fileDescr) {
-        selected.push_back (fileDescr);
-        fileDescr->selected = true;
+inline void addToSelection (ThumbBrowserEntryBase* entry, ThumbVector& selected)
+{
+    if (entry->selected || entry->filtered)
+        return;
+
+    entry->selected = true;
+    selected.push_back (entry);
+}
+
+inline void removeFromSelection (const ThumbIterator& iterator, ThumbVector& selected)
+{
+    (*iterator)->selected = false;
+    selected.erase (iterator);
+}
+
+}
+
+void ThumbBrowserBase::selectSingle (ThumbBrowserEntryBase* clicked)
+{
+    clearSelection (selected);
+
+    if (clicked)
+        addToSelection (clicked, selected);
+}
+
+void ThumbBrowserBase::selectRange (ThumbBrowserEntryBase* clicked, bool additional)
+{
+    if (selected.empty ()) {
+        addToSelection (clicked, selected);
+        return;
+    }
+
+    if (!additional || !lastClicked) {
+        // Extend the current range w.r.t to first selected entry.
+        ThumbIterator front = std::find (fd.begin (), fd.end (), selected.front ());
+        ThumbIterator current = std::find (fd.begin (), fd.end (), clicked);
+
+        if (front > current)
+            std::swap (front, current);
+
+        clearSelection (selected);
+
+        for (; front <= current; ++front)
+            addToSelection (*front, selected);
+    } else {
+        // Add an additional range w.r.t. the last clicked entry.
+        ThumbIterator last = std::find (fd.begin (), fd.end (), lastClicked);
+        ThumbIterator current = std::find (fd.begin (), fd.end (), clicked);
+
+        if (last > current)
+            std::swap (last, current);
+
+        for (; last <= current; ++last)
+            addToSelection (*last, selected);
     }
 }
 
-void ThumbBrowserBase::selectRange (ThumbBrowserEntryBase* fileDescr)
+void ThumbBrowserBase::selectSet (ThumbBrowserEntryBase* clicked)
 {
-    if (selected.empty()) {
-        selected.push_back (fileDescr);
-        fileDescr->selected = true;
+    const ThumbIterator iterator = std::find (selected.begin (), selected.end (), clicked);
+
+    if (iterator != selected.end ()) {
+        removeFromSelection (iterator, selected);
     } else {
-        // find the start and the end of the selection interval
-        size_t startx = fd.size() - 1;
-
-        if (lastClicked) {
-            for (; startx > 0; startx--)
-                if (fd[startx] == lastClicked) {
-                    break;
-                }
-        } else {
-            for (; startx > 0; startx--)
-                if (fd[startx] == selected[0]) {
-                    break;
-                }
-        }
-
-        size_t endx = 0;
-
-        for (; endx < fd.size(); endx++)
-            if (fd[endx] == fileDescr) {
-                break;
-            }
-
-        if (endx < startx) {
-            int tmp = endx;
-            endx = startx;
-            startx = tmp;
-        }
-
-        // clear current selection
-        for (size_t i = 0; i < selected.size(); i++) {
-            selected[i]->selected = false;
-        }
-
-        selected.clear ();
-
-        // select thumbnails in the interval
-        for (size_t i = startx; i <= endx; i++) {
-            if (!fd[i]->filtered) {
-                fd[i]->selected = true;
-                selected.push_back (fd[i]);
-            }
-        }
-    }
-}
-
-void ThumbBrowserBase::selectSet (ThumbBrowserEntryBase* fileDescr)
-{
-    std::vector<ThumbBrowserEntryBase*>::iterator i = std::find (selected.begin(), selected.end(), fileDescr);
-
-    if (i != selected.end()) {
-        (*i)->selected = false;
-        selected.erase (i);
-    } else {
-        selected.push_back (fileDescr);
-        fileDescr->selected = true;
+        addToSelection (clicked, selected);
     }
 }
 
@@ -828,7 +832,7 @@ void ThumbBrowserBase::buttonPressed (int x, int y, int button, GdkEventType typ
             doubleClicked (selected[0]);
         } else if (button == 1 && type == GDK_BUTTON_PRESS) {
             if (fileDescr && (state & GDK_SHIFT_MASK))
-                selectRange (fileDescr);
+                selectRange (fileDescr, state & GDK_CONTROL_MASK);
             else if (fileDescr && (state & GDK_CONTROL_MASK))
                 selectSet (fileDescr);
             else
diff --git a/rtgui/thumbbrowserbase.h b/rtgui/thumbbrowserbase.h
index ee11f550e..a3ef08d80 100644
--- a/rtgui/thumbbrowserbase.h
+++ b/rtgui/thumbbrowserbase.h
@@ -111,9 +111,9 @@ public:
     void scrollPage (int direction);
 
 private:
-    void selectSingle (ThumbBrowserEntryBase* fileDescr);
-    void selectRange (ThumbBrowserEntryBase* fileDescr);
-    void selectSet (ThumbBrowserEntryBase* fileDescr);
+    void selectSingle (ThumbBrowserEntryBase* clicked);
+    void selectRange (ThumbBrowserEntryBase* clicked, bool additional);
+    void selectSet (ThumbBrowserEntryBase* clicked);
 
 public:
     void selectPrev (int distance, bool enlarge);