diff --git a/src/common/tbarbase.cpp b/src/common/tbarbase.cpp
index f944cdd209..40c84a74cc 100644
--- a/src/common/tbarbase.cpp
+++ b/src/common/tbarbase.cpp
@@ -146,8 +146,10 @@ wxToolBarBase::wxToolBarBase()
 {
     // the list owns the pointers
     m_xMargin = m_yMargin = 0;
-
     m_maxRows = m_maxCols = 0;
+    m_toolPacking = m_toolSeparation = 0;
+    m_defaultWidth = 16;
+    m_defaultHeight = 15;
 }
 
 wxToolBarToolBase *wxToolBarBase::DoAddTool(int id,