diff --git a/SurfAux.cpp b/SurfAux.cpp
index ada55d4..a21fca0 100644
--- a/SurfAux.cpp
+++ b/SurfAux.cpp
@@ -69,9 +69,13 @@ NurbsSurfaceCanonicalize( SNurbsSurfData& snData)
                if ( snData.bRat)
                   snData.mW.resize( nuCurve.vW.size()) ;
             }
-            for ( int i = 0 ; i < snData.nCPU ; ++i) {
+            for ( int i = 0 ; i < int( nuCurve.vCP.size()) ; ++i) {
+               if( snData.mCP[i].size() == 0)
+                  snData.mCP[i].resize( snData.nCPV) ;
                snData.mCP[i][j] = nuCurve.vCP[i] ;
                if ( snData.bRat) {
+                  if( snData.mW[i].size() == 0)
+                     snData.mW[i].resize( snData.nCPV) ;
                   snData.mW[i][j] = nuCurve.vW[i] ;
                   snData.mCP[i][j] *= nuCurve.vW[i] ;
                }