diff --git a/rtgui/editorpanel.cc b/rtgui/editorpanel.cc
index 8abbe6e27..8dba7e38e 100644
--- a/rtgui/editorpanel.cc
+++ b/rtgui/editorpanel.cc
@@ -1968,11 +1968,12 @@ void EditorPanel::histogramChanged (LUTu & histRed, LUTu & histGreen, LUTu & his
 bool EditorPanel::CheckSidePanelsVisibility()
 {
     if (tbTopPanel_1) {
-        return !(!tbTopPanel_1->get_active() && !tbRightPanel_1->get_active() && !hidehp->get_active());
+        return tbTopPanel_1->get_active() || tbRightPanel_1->get_active() || hidehp->get_active();
     }
 
-    return !(!tbRightPanel_1->get_active() && !hidehp->get_active());
+    return tbRightPanel_1->get_active() || hidehp->get_active();
 }
+
 void EditorPanel::toggleSidePanels()
 {
     // Maximize preview panel:
diff --git a/rtgui/filecatalog.cc b/rtgui/filecatalog.cc
index 0c58b3038..97407fb1e 100644
--- a/rtgui/filecatalog.cc
+++ b/rtgui/filecatalog.cc
@@ -2123,8 +2123,9 @@ void FileCatalog::tbRightPanel_1_toggled ()
 
 bool FileCatalog::CheckSidePanelsVisibility()
 {
-    return !(!tbLeftPanel_1->get_active() && !tbRightPanel_1->get_active());
+    return tbLeftPanel_1->get_active() || tbRightPanel_1->get_active();
 }
+
 void FileCatalog::toggleSidePanels()
 {
     // toggle left AND right panels
diff --git a/rtgui/progressconnector.h b/rtgui/progressconnector.h
index fce1f17f5..f62b645c3 100644
--- a/rtgui/progressconnector.h
+++ b/rtgui/progressconnector.h
@@ -90,7 +90,7 @@ class ProgressConnector
 
 public:
 
-    ProgressConnector (): retval( nullptr ), workThread( nullptr ) { }
+    ProgressConnector (): retval( 0 ), workThread( nullptr ) { }
 
     void startFunc (const sigc::slot0<T>& startHandler, const sigc::slot0<bool>& endHandler )
     {