diff --git a/src/ribbon/panel.cpp b/src/ribbon/panel.cpp
index 99f69bcd1d..6964788a35 100644
--- a/src/ribbon/panel.cpp
+++ b/src/ribbon/panel.cpp
@@ -671,6 +671,10 @@ bool wxRibbonPanel::Realize()
 
     wxSize minimum_children_size(0, 0);
 
+    // Reset it before calling GetPanelSizerMinSize() below as it shouldn't use
+    // the old value, if we had any.
+    m_smallest_unminimised_size = wxDefaultSize;
+
     // Ask sizer if there is one present
     if(GetSizer())
     {