diff --git a/graf3d/g3d/src/TView3D.cxx b/graf3d/g3d/src/TView3D.cxx
index fc5abbf5b2f75d6410a329f0ffc15d251927fe16..6f54bfaf60b05eb0f7622b30fd2ace9ac3e02ab7 100644
--- a/graf3d/g3d/src/TView3D.cxx
+++ b/graf3d/g3d/src/TView3D.cxx
@@ -336,8 +336,8 @@ void TView3D::AxisVertex(Double_t, Double_t *av, Int_t &ix1, Int_t &ix2, Int_t &
 
    //        Set vertices
    Int_t icase = 0;
-   if (fTnorm[ 8] < 0) icase += 1; // z projection of (1,0,0)
-   if (fTnorm[ 9] < 0) icase += 2; // z projection of (0,1,0)
+   if (fTnorm[ 8] <= 0) icase += 1; // z projection of (1,0,0)
+   if (fTnorm[ 9] <= 0) icase += 2; // z projection of (0,1,0)
    for (Int_t i=0; i<8; ++i) {
       Int_t k = inodes[icase][i] - 1;
       av[i*3+0] = p[k][0];