diff --git a/src/glu/sgi/libnurbs/internals/uarray.cc b/src/glu/sgi/libnurbs/internals/uarray.cc
index f0e23643737..4b3329c0f27 100644
--- a/src/glu/sgi/libnurbs/internals/uarray.cc
+++ b/src/glu/sgi/libnurbs/internals/uarray.cc
@@ -47,6 +47,7 @@ Uarray::Uarray( void )
 {
     uarray = 0;
     size = 0;
+    ulines = 0;
 }
 
 Uarray::~Uarray( void )