diff --git a/etgtools/tweaker_tools.py b/etgtools/tweaker_tools.py
index 9238a130..663bc0d9 100644
--- a/etgtools/tweaker_tools.py
+++ b/etgtools/tweaker_tools.py
@@ -434,6 +434,10 @@ def fixSizerClass(klass):
     removeVirtuals(klass)
     klass.find('CalcMin').isVirtual = True
     klass.find('RepositionChildren').isVirtual = True
+    try:
+        klass.find('InformFirstDirection').isVirtual = True
+    except extractors.ExtractorError:
+        pass
 
     # in the wxSizer class it is pure-virtual
     if klass.name == 'wxSizer':