diff --git a/apps/openmw/mwgui/mapwindow.cpp b/apps/openmw/mwgui/mapwindow.cpp
index 1968181ceb..d93b01ce43 100644
--- a/apps/openmw/mwgui/mapwindow.cpp
+++ b/apps/openmw/mwgui/mapwindow.cpp
@@ -844,6 +844,15 @@ namespace MWGui
         }
     }
 
+    void MapWindow::setAlpha(float alpha)
+    {
+        NoDrop::setAlpha(alpha);
+        // can't allow showing map with partial transparency, as the fog of war will also go transparent
+        // and reveal parts of the map you shouldn't be able to see
+        for (std::vector<MyGUI::ImageBox*>::iterator it = mMapWidgets.begin(); it != mMapWidgets.end(); ++it)
+            (*it)->setVisible(alpha == 1);
+    }
+
     // -------------------------------------------------------------------
 
     EditNoteDialog::EditNoteDialog()
diff --git a/apps/openmw/mwgui/mapwindow.hpp b/apps/openmw/mwgui/mapwindow.hpp
index a9edbe0b1e..08a9118a96 100644
--- a/apps/openmw/mwgui/mapwindow.hpp
+++ b/apps/openmw/mwgui/mapwindow.hpp
@@ -171,6 +171,8 @@ namespace MWGui
 
         void setCellName(const std::string& cellName);
 
+        virtual void setAlpha(float alpha);
+
         void renderGlobalMap(Loading::Listener* loadingListener);
 
         // adds the marker to the global map
diff --git a/apps/openmw/mwgui/windowbase.cpp b/apps/openmw/mwgui/windowbase.cpp
index 4af0afc1f6..c4bda0baed 100644
--- a/apps/openmw/mwgui/windowbase.cpp
+++ b/apps/openmw/mwgui/windowbase.cpp
@@ -96,11 +96,16 @@ void NoDrop::onFrame(float dt)
     if (mTransparent)
     {
         mWidget->setNeedMouseFocus(false); // Allow click-through
-        mWidget->setAlpha(std::max(0.13f, mWidget->getAlpha() - dt*5));
+        setAlpha(std::max(0.13f, mWidget->getAlpha() - dt*5));
     }
     else
     {
         mWidget->setNeedMouseFocus(true);
-        mWidget->setAlpha(std::min(1.0f, mWidget->getAlpha() + dt*5));
+        setAlpha(std::min(1.0f, mWidget->getAlpha() + dt*5));
     }
 }
+
+void NoDrop::setAlpha(float alpha)
+{
+    mWidget->setAlpha(alpha);
+}
diff --git a/apps/openmw/mwgui/windowbase.hpp b/apps/openmw/mwgui/windowbase.hpp
index 53b10b452e..bf74c8bf0f 100644
--- a/apps/openmw/mwgui/windowbase.hpp
+++ b/apps/openmw/mwgui/windowbase.hpp
@@ -55,6 +55,7 @@ namespace MWGui
         NoDrop(DragAndDrop* drag, MyGUI::Widget* widget);
 
         void onFrame(float dt);
+        virtual void setAlpha(float alpha);
 
     private:
         MyGUI::Widget* mWidget;