diff --git a/include/wx/tbarbase.h b/include/wx/tbarbase.h
index 137f86579c..bbfd06cf68 100644
--- a/include/wx/tbarbase.h
+++ b/include/wx/tbarbase.h
@@ -465,8 +465,8 @@ public:
     int GetMaxRows() const { return m_maxRows; }
     int GetMaxCols() const { return m_maxCols; }
 
-    // get/set the size of the bitmaps used by the toolbar: should be called
-    // before adding any tools to the toolbar
+    // get/set the size of the bitmaps used by the toolbar, in logical pixels:
+    // should be called before realizing the toolbar if it's called at all
     virtual void SetToolBitmapSize(const wxSize& size);
     virtual wxSize GetToolBitmapSize() const;
 
@@ -704,13 +704,14 @@ protected:
     int m_toolPacking,
         m_toolSeparation;
 
-    // the currently used size of the toolbar bitmaps: the name is unfortunate
-    // but keep it for compatibility
+    // the currently used size of the toolbar bitmaps in logical pixels: the
+    // name is unfortunate but keep it for compatibility
     wxCoord m_defaultWidth, m_defaultHeight;
 
 private:
     // the size of the bitmaps requested by the application by calling
-    // SetToolBitmapSize()
+    // SetToolBitmapSize() expressed in DIPs because we want to keep using the
+    // same value even if the DPI changes
     wxSize m_requestedBitmapSize;
 
     wxDECLARE_EVENT_TABLE();
diff --git a/interface/wx/toolbar.h b/interface/wx/toolbar.h
index ee04b873fd..8392a2cec7 100644
--- a/interface/wx/toolbar.h
+++ b/interface/wx/toolbar.h
@@ -878,19 +878,24 @@ public:
     //@}
 
     /**
-        Sets the default size of each tool bitmap. The default bitmap size is 16
-        by 15 pixels.
+        Sets the default size of each tool bitmap.
 
         It is usually unnecessary to call this function, as the tools will
         always be made big enough to fit the size of the bitmaps used in them.
 
-        If you do call it, note that @a size does @e not need to be multiplied
-        by the DPI-dependent factor even under MSW, where it would normally be
-        necessary, as the toolbar adjusts this size to the current DPI
-        automatically.
+        If you do call it, it must be done before toolbar is Realize()'d.
+
+        Example of using this function to force the bitmaps to be at least
+        32 pixels wide and tall:
+        @code
+            toolbar->SetToolBitmapSize(FromDIP(wxSize(32, 32)));
+            toolbar->AddTool(wxID_NEW, "New", wxBitmapBundle::FromXXX(...));
+            ...
+            toolbar->Realize();
+        @endcode
 
         @param size
-            The size of the bitmaps in the toolbar.
+            The size of the bitmaps in the toolbar in logical pixels.
 
         @see GetToolBitmapSize(), GetToolSize()
     */
diff --git a/samples/toolbar/toolbar.cpp b/samples/toolbar/toolbar.cpp
index 0aebe56c2a..bcccae2a30 100644
--- a/samples/toolbar/toolbar.cpp
+++ b/samples/toolbar/toolbar.cpp
@@ -438,10 +438,12 @@ void MyFrame::PopulateToolbar(wxToolBarBase* toolBar)
     toolBarBitmaps[Tool_about] = wxBitmapBundle::FromSVG(svg_data, sizeBitmap);
 #endif // wxHAS_SVG
 
-    // Note that there is no need for FromDIP() here, wxMSW will adjust the
-    // size on its own and under the other platforms there is no need for
-    // scaling the coordinates anyhow.
-    toolBar->SetToolBitmapSize(sizeBitmap);
+    // We don't have to call this function at all when using the default bitmap
+    // size (i.e. when m_smallToolbar == true), but it's harmless to do it.
+    //
+    // Note that sizeBitmap is in DIPs, so we need to use FromDIP() to scale it
+    // up for the current DPI, if necessary.
+    toolBar->SetToolBitmapSize(FromDIP(sizeBitmap));
 
     toolBar->AddTool(wxID_NEW, "New",
                      toolBarBitmaps[Tool_new], wxNullBitmap, wxITEM_DROPDOWN,
diff --git a/src/common/tbarbase.cpp b/src/common/tbarbase.cpp
index 4bbe762195..1aaf478555 100644
--- a/src/common/tbarbase.cpp
+++ b/src/common/tbarbase.cpp
@@ -440,7 +440,9 @@ void wxToolBarBase::DoSetToolBitmapSize(const wxSize& size)
 
 void wxToolBarBase::SetToolBitmapSize(const wxSize& size)
 {
-    m_requestedBitmapSize = size;
+    // We store this value in DIPs to avoid having to update it when the DPI
+    // changes.
+    m_requestedBitmapSize = ToDIP(size);
 
     DoSetToolBitmapSize(size);
 }
@@ -479,28 +481,27 @@ void wxToolBarBase::AdjustToolBitmapSize()
                                (
                                 this,
                                 bundles,
-                                sizeOrig
+                                ToDIP(sizeOrig)
                                );
 
-        // Don't do anything if it doesn't change, our current size is supposed
-        // to satisfy any constraints we might have anyhow.
-        if ( sizePreferred == sizeOrig )
-            return;
-
-        // This size is supposed to be in logical units for the platforms where
-        // they differ from physical ones, so convert it.
+        // GetConsensusSizeFor() returns physical size, but we want to operate
+        // with logical pixels as everything else is expressed in them.
         //
         // Note that this could introduce rounding problems but, in fact,
         // neither wxGTK nor wxOSX (that are the only ports where contents
         // scale factor may be different from 1) use this size at all
         // currently, so it shouldn't matter. But if/when they are modified to
         // use the size computed here, this would need to be revisited.
-        sizePreferred /= GetContentScaleFactor();
+        sizePreferred = FromPhys(sizePreferred);
 
         // Don't decrease the bitmap below the size requested by the application
         // as using larger bitmaps shouldn't shrink them to the small default
         // size.
-        sizePreferred.IncTo(m_requestedBitmapSize);
+        sizePreferred.IncTo(FromDIP(m_requestedBitmapSize));
+
+        // No need to change the bitmaps size if it doesn't really change.
+        if ( sizePreferred == sizeOrig )
+            return;
 
         // Call DoSetToolBitmapSize() and not SetToolBitmapSize() to avoid
         // changing the requested bitmap size: if we set our own adjusted size