diff --git a/rtdata/languages/default b/rtdata/languages/default
index 8fa85f144..835831547 100644
--- a/rtdata/languages/default
+++ b/rtdata/languages/default
@@ -1914,7 +1914,9 @@ PREFERENCES_INTERNALTHUMBIFUNTOUCHED;Show embedded JPEG thumbnail if raw is uned
 PREFERENCES_LANG;Language
 PREFERENCES_LANGAUTODETECT;Use system language
 PREFERENCES_LENSFUNDBDIR;Lensfun database directory
+PREFERENCES_LENSFUNDBDIR_TOOLTIP;Directory containing the Lensfun database.  Leave empty to use the default directories.
 PREFERENCES_LENSPROFILESDIR;Lens profiles directory
+PREFERENCES_LENSPROFILESDIR_TOOLTIP;Directory containing Adobe Lens Correction Profiles (LCPs)
 PREFERENCES_MAXRECENTFOLDERS;Maximum number of recent folders
 PREFERENCES_MENUGROUPEXTPROGS;Group 'Open with'
 PREFERENCES_MENUGROUPFILEOPERATIONS;Group 'File operations'
diff --git a/rtgui/preferences.cc b/rtgui/preferences.cc
index da8272442..82ef67d2f 100644
--- a/rtgui/preferences.cc
+++ b/rtgui/preferences.cc
@@ -660,6 +660,7 @@ Gtk::Widget* Preferences::getImageProcessingPanel ()
 
 	//Lens Profiles Dir
     Gtk::Label *lensProfilesDirLabel = Gtk::manage(new Gtk::Label(M("PREFERENCES_LENSPROFILESDIR") + ":"));
+    lensProfilesDirLabel->set_tooltip_text(M("PREFERENCES_LENSPROFILESDIR_TOOLTIP"));
     setExpandAlignProperties(lensProfilesDirLabel, false, false, Gtk::ALIGN_START, Gtk::ALIGN_CENTER);
     lensProfilesDir = Gtk::manage(new MyFileChooserButton(M("PREFERENCES_LENSPROFILESDIR"), Gtk::FILE_CHOOSER_ACTION_SELECT_FOLDER));
     setExpandAlignProperties(lensProfilesDir, true, false, Gtk::ALIGN_FILL, Gtk::ALIGN_CENTER);
@@ -669,6 +670,7 @@ Gtk::Widget* Preferences::getImageProcessingPanel ()
 
     // Lensfun DB dir
     Gtk::Label *lensfunDbDirLabel = Gtk::manage(new Gtk::Label(M("PREFERENCES_LENSFUNDBDIR") + ":"));
+    lensfunDbDirLabel->set_tooltip_text(M("PREFERENCES_LENSFUNDBDIR_TOOLTIP"));
     setExpandAlignProperties(lensfunDbDirLabel, false, false, Gtk::ALIGN_START, Gtk::ALIGN_CENTER);
     lensfunDbDir = Gtk::manage(new MyFileChooserEntry(M("PREFERENCES_LENSFUNDBDIR"), Gtk::FILE_CHOOSER_ACTION_SELECT_FOLDER));
     lensfunDbDir->set_placeholder_text(Glib::ustring::compose("(%1)", M("GENERAL_AUTO")));