diff --git a/plugins/extensions/separate_channels/dlg_separate.cc b/plugins/extensions/separate_channels/dlg_separate.cc
index ea9fb296bc..582e0c28ac 100644
--- a/plugins/extensions/separate_channels/dlg_separate.cc
+++ b/plugins/extensions/separate_channels/dlg_separate.cc
@@ -1,116 +1,124 @@
 /*
  *  dlg_separate.cc - part of KimageShop^WKrayon^WKrita
  *
  *  Copyright (c) 2004 Boudewijn Rempt <boud@valdyas.org>
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
  *  the Free Software Foundation; either version 2 of the License, or
  *  (at your option) any later version.
  *
  *  This program is distributed in the hope that it will be useful,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  *  GNU General Public License for more details.
  *
  *  You should have received a copy of the GNU General Public License
  *  along with this program; if not, write to the Free Software
  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
 
 #include "dlg_separate.h"
 
 #include <QRadioButton>
 #include <QCheckBox>
 #include <QLabel>
 #include <QComboBox>
 
 #include <klocalizedstring.h>
 #include <kis_debug.h>
 DlgSeparate::DlgSeparate(const QString & imageCS,
                          const QString & layerCS,
                          QWidget *  parent,
                          const char * name)
         : KoDialog(parent)
         , m_imageCS(imageCS)
         , m_layerCS(layerCS)
 {
     setObjectName(name);
     setCaption(i18n("Separate Image"));
     setButtons(Ok | Cancel);
     setDefaultButton(Ok);
 
     m_page = new WdgSeparations(this);
     Q_CHECK_PTR(m_page);
     setMainWidget(m_page);
     resize(m_page->sizeHint());
 
     m_page->lblColormodel->setText(layerCS);
     m_page->grpOutput->hide();
     connect(m_page->radioCurrentLayer, SIGNAL(toggled(bool)), this, SLOT(slotSetColorSpaceLabel()));
     connect(m_page->radioAllLayers, SIGNAL(toggled(bool)), this, SLOT(slotSetColorSpaceLabel()));
-    connect(m_page->chkColors, SIGNAL(toggled(bool)), m_page->chkDownscale, SLOT(setDisabled(bool)));
+    connect(m_page->chkColors, SIGNAL(toggled(bool)), this, SLOT(disableDownScaleIfPossible(bool)));
 
     connect(this, SIGNAL(okClicked()),
             this, SLOT(okClicked()));
 }
 
 DlgSeparate::~DlgSeparate()
 {
     delete m_page;
 }
 enumSepAlphaOptions DlgSeparate::getAlphaOptions()
 {
     if (m_page->radioCopyAlpha->isChecked()) return COPY_ALPHA_TO_SEPARATIONS;
     if (m_page->radioDiscardAlpha->isChecked()) return DISCARD_ALPHA;
     if (m_page->radioSeparateAlpha->isChecked()) return CREATE_ALPHA_SEPARATION;
 
     return COPY_ALPHA_TO_SEPARATIONS;
 }
 
 enumSepSource DlgSeparate::getSource()
 {
     if (m_page->radioCurrentLayer->isChecked()) return CURRENT_LAYER;
     if (m_page->radioAllLayers->isChecked()) return ALL_LAYERS;
     //if (XXX) return VISIBLE_LAYERS;
 
     return CURRENT_LAYER;
 }
 
 enumSepOutput DlgSeparate::getOutput()
 {
     if (m_page->radioLayers->isChecked()) return TO_LAYERS;
     if (m_page->radioImages->isChecked()) return TO_IMAGES;
 
     return TO_LAYERS;
 }
 
 
 bool DlgSeparate::getDownscale()
 {
     return m_page->chkDownscale->isChecked();
 }
 
 bool DlgSeparate::getToColor()
 {
     return m_page->chkColors->isChecked();
 }
 
 void DlgSeparate::okClicked()
 {
     accept();
 }
 
+void DlgSeparate::disableDownScaleIfPossible(bool disable)
+{
+    if (m_canDownScale) {
+        m_page->chkDownscale->setDisabled(disable);
+    }
+}
+
 void DlgSeparate::slotSetColorSpaceLabel()
 {
     if (m_page->radioCopyAlpha->isChecked()) {
         m_page->lblColormodel->setText(m_layerCS);
     } else if (m_page->radioAllLayers->isChecked()) {
         m_page->lblColormodel->setText(m_imageCS);
     }
 }
 void DlgSeparate::enableDownscale(bool enable)
 {
+    m_canDownScale = enable;
     m_page->chkDownscale->setEnabled(enable);
 }
 
diff --git a/plugins/extensions/separate_channels/dlg_separate.h b/plugins/extensions/separate_channels/dlg_separate.h
index 020a628325..29acc922ea 100644
--- a/plugins/extensions/separate_channels/dlg_separate.h
+++ b/plugins/extensions/separate_channels/dlg_separate.h
@@ -1,75 +1,77 @@
 /*
  *  dlg_imagesize.h -- part of KimageShop^WKrayon^WKrita
  *
  *  Copyright (c) 2005 Boudewijn Rempt <boud@valdyas.org>
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
  *  the Free Software Foundation; either version 2 of the License, or
  *  (at your option) any later version.
  *
  *  This program is distributed in the hope that it will be useful,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  *  GNU General Public License for more details.
  *
  *  You should have received a copy of the GNU General Public License
  *  along with this program; if not, write to the Free Software
  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
 #ifndef DLG_SEPARATE
 #define DLG_SEPARATE
 
 #include <KoDialog.h>
 #include <kis_channel_separator.h>
 #include "ui_wdg_separations.h"
 
 class WdgSeparations : public QWidget, public Ui::WdgSeparations
 {
 public:
     WdgSeparations(QWidget *parent) : QWidget(parent) {
         setupUi(this);
     }
 };
 
 /**
  * This dialog allows the user to configure the decomposition of an image
  * into layers: one layer for each color channel.
  */
 class DlgSeparate: public KoDialog
 {
 
     Q_OBJECT
 
 public:
 
     DlgSeparate(const QString & imageCS, const QString & layerCS, QWidget * parent = 0,
                 const char* name = 0);
     ~DlgSeparate() override;
 
 public:
 
     enumSepAlphaOptions getAlphaOptions();
     enumSepSource getSource();
     enumSepOutput getOutput();
 
     bool getDownscale();
     void enableDownscale(bool enable);
 
     bool getToColor();
 
 
 private Q_SLOTS:
 
     void slotSetColorSpaceLabel();
     void okClicked();
+    void disableDownScaleIfPossible(bool disable);
 
 private:
 
     WdgSeparations * m_page;
     QString m_imageCS;
     QString m_layerCS;
+    bool m_canDownScale {true};
 
 };
 
 #endif // DLG_SEPARATE