diff --git a/pandatool/src/eggbase/eggBase.cxx b/pandatool/src/eggbase/eggBase.cxx
index 92e12abbbe..cb6f948cf8 100644
--- a/pandatool/src/eggbase/eggBase.cxx
+++ b/pandatool/src/eggbase/eggBase.cxx
@@ -42,6 +42,8 @@ EggBase() {
   _normals_mode = NM_preserve;
   _normals_threshold = 0.0;
 
+  _got_tbnall = false;
+
   _got_transform = false;
   _transform = LMatrix4d::ident_mat();