diff --git a/docs/doxygen/overviews/high_dpi.md b/docs/doxygen/overviews/high_dpi.md
index ffc6e8fed0..58960a1a09 100644
--- a/docs/doxygen/overviews/high_dpi.md
+++ b/docs/doxygen/overviews/high_dpi.md
@@ -299,7 +299,8 @@ programs involves doing at least the following:
    wxArtProvider::CreateBitmapBundle() (and, of course, return multiple bitmaps
    from it) instead of wxArtProvider::CreateBitmap().
 4. Removing any calls to wxToolBar::SetToolBitmapSize() or, equivalently,
-   `<bitmapsize>` attributes from the XRC, as this forces unwanted scaling.
+   `<bitmapsize>` attributes from the XRC, as this overrides the best size
+   determination and may result in suboptimal appearance.
 
 
 
diff --git a/interface/wx/toolbar.h b/interface/wx/toolbar.h
index c021c1ec56..d67c92b178 100644
--- a/interface/wx/toolbar.h
+++ b/interface/wx/toolbar.h
@@ -882,15 +882,15 @@ public:
 
         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.
-        Moreover, calling it may force wxToolBar to scale its images, even
-        using non-integer scaling factor, which will usually look bad, instead
-        of adapting the image size to the current DPI scaling in order to avoid
-        doing this.
+        Moreover, calling it forces wxToolBar to scale its images in high DPI
+        using the provided size, instead of letting wxBitmapBundle used for the
+        tool bitmaps determine the best suitable bitmap size, which may result
+        in suboptimal appearance.
 
         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:
+        32 pixels wide and tall (at normal DPI):
         @code
             toolbar->SetToolBitmapSize(FromDIP(wxSize(32, 32)));
             toolbar->AddTool(wxID_NEW, "New", wxBitmapBundle::FromXXX(...));
@@ -898,9 +898,6 @@ public:
             toolbar->Realize();
         @endcode
 
-        Note that this example would scale bitmaps to 48 pixels when using 150%
-        DPI scaling, which wouldn't happen without calling SetToolBitmapSize().
-
         @param size
             The size of the bitmaps in the toolbar in logical pixels.
 
diff --git a/src/common/tbarbase.cpp b/src/common/tbarbase.cpp
index 1aaf478555..673022012a 100644
--- a/src/common/tbarbase.cpp
+++ b/src/common/tbarbase.cpp
@@ -475,7 +475,23 @@ void wxToolBarBase::AdjustToolBitmapSize()
             bundles.push_back(bmp);
     }
 
-    if ( !bundles.empty() )
+    if ( bundles.empty() )
+        return;
+
+    wxSize sizeNeeded;
+
+    if ( m_requestedBitmapSize != wxSize(0, 0) )
+    {
+        // If we have a fixed requested bitmap size, use it, but scale it by
+        // integer factor only, as otherwise we'd force fractional (and hence
+        // ugly looking) scaling here whenever fractional DPI scaling is used.
+
+        // We want to round 1.5 down to 1, but 1.75 up to 2.
+        int scaleFactorRoundedDown =
+            static_cast<int>(ceil(2*GetDPIScaleFactor())) / 2;
+        sizeNeeded = m_requestedBitmapSize*scaleFactorRoundedDown;
+    }
+    else // Determine the best size to use from the bitmaps we have.
     {
         wxSize sizePreferred = wxBitmapBundle::GetConsensusSizeFor
                                (
@@ -492,22 +508,17 @@ void wxToolBarBase::AdjustToolBitmapSize()
         // 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 = 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(FromDIP(m_requestedBitmapSize));
-
-        // No need to change the bitmaps size if it doesn't really change.
-        if ( sizePreferred == sizeOrig )
-            return;
+        sizeNeeded = FromPhys(sizePreferred);
+    }
 
+    // No need to change the bitmaps size if it doesn't really change.
+    if ( sizeNeeded != sizeOrig )
+    {
         // Call DoSetToolBitmapSize() and not SetToolBitmapSize() to avoid
         // changing the requested bitmap size: if we set our own adjusted size
         // as the preferred one, we wouldn't decrease it later even if we ought
         // to, as when moving from a monitor with higher DPI to a lower-DPI one.
-        DoSetToolBitmapSize(sizePreferred);
+        DoSetToolBitmapSize(sizeNeeded);
     }
 }