diff --git a/interface/wx/toolbar.h b/interface/wx/toolbar.h
index 5630aca98f..79449c8638 100644
--- a/interface/wx/toolbar.h
+++ b/interface/wx/toolbar.h
@@ -594,6 +594,11 @@ public:
         usually unnecessary to call either this function or
         SetToolBitmapSize() at all.
 
+        This function returns the size in logical pixels, for consistency with
+        SetToolBitmapSize() which takes size in logical pixels. See @ref
+        overview_high_dpi for more information about the different pixel types
+        and how to convert between them.
+
         @remarks Note that this is the size of the bitmap you pass to AddTool(),
             and not the eventual size of the tool button.
 
diff --git a/src/common/tbarbase.cpp b/src/common/tbarbase.cpp
index 1ef80ae35d..04c8057b9c 100644
--- a/src/common/tbarbase.cpp
+++ b/src/common/tbarbase.cpp
@@ -486,7 +486,7 @@ void wxToolBarBase::AdjustToolBitmapSize()
         // 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;
+        sizeNeeded = FromPhys(m_requestedBitmapSize*scaleFactorRoundedDown);
     }
     else // Determine the best size to use from the bitmaps we have.
     {