diff --git a/rtdata/languages/default b/rtdata/languages/default
index 694666055..d8666951e 100644
--- a/rtdata/languages/default
+++ b/rtdata/languages/default
@@ -2475,6 +2475,7 @@ TP_LOCALLAB_HLH;Curves H
 TP_LOCALLAB_IND;Independent (mouse)
 TP_LOCALLAB_INDSL;Independent (mouse + sliders)
 TP_LOCALLAB_INVERS;Inverse
+TP_LOCALLAB_INVERS_TOOLTIP;If selected (inverse) less possibilities.\n\nAlternative\nFirst Spot:\n full picture - delimiter outside preview\n Shape RT-spot area : rectangle. Transition 100\n\nSecond spot : Excluding spot
 TP_LOCALLAB_ISOGR;Coarseness (ISO)
 TP_LOCALLAB_LABEL;Local Adjustments
 TP_LOCALLAB_LABBLURM;Mask Blur
diff --git a/rtgui/locallabtools.cc b/rtgui/locallabtools.cc
index 2b1c8c826..cd8ba0ac4 100644
--- a/rtgui/locallabtools.cc
+++ b/rtgui/locallabtools.cc
@@ -498,6 +498,7 @@ LocallabColor::LocallabColor():
     softradiuscol->setAdjusterListener(this);
 
     inversConn = invers->signal_toggled().connect(sigc::mem_fun(*this, &LocallabColor::inversChanged));
+    invers->set_tooltip_text(M("TP_LOCALLAB_INVERS_TOOLTIP"));
 
     setExpandAlignProperties(expgradcol, true, false, Gtk::ALIGN_FILL, Gtk::ALIGN_START);
 
@@ -2268,6 +2269,7 @@ LocallabExposure::LocallabExposure():
     softradiusexp->setAdjusterListener(this);
 
     inversexConn  = inversex->signal_toggled().connect(sigc::mem_fun(*this, &LocallabExposure::inversexChanged));
+    inversex->set_tooltip_text(M("TP_LOCALLAB_INVERS_TOOLTIP"));
 
     setExpandAlignProperties(expmaskexp, true, false, Gtk::ALIGN_FILL, Gtk::ALIGN_START);
 
@@ -3294,6 +3296,7 @@ LocallabShadow::LocallabShadow():
     angSH->set_tooltip_text(M("TP_LOCALLAB_GRADANG_TOOLTIP"));
 
     inversshConn = inverssh->signal_toggled().connect(sigc::mem_fun(*this, &LocallabShadow::inversshChanged));
+    inverssh->set_tooltip_text(M("TP_LOCALLAB_INVERS_TOOLTIP"));
 
     setExpandAlignProperties(expmasksh, true, false, Gtk::ALIGN_FILL, Gtk::ALIGN_START);