diff --git a/lib/lbfgs.c b/lib/lbfgs.c
index 1ef0ca7..47ec347 100644
--- a/lib/lbfgs.c
+++ b/lib/lbfgs.c
@@ -561,6 +561,7 @@ int lbfgs(
             vecncpy(d, g, n);
         } else {
             owlqn_direction(d, x, g, param.orthantwise_c, param.orthantwise_start, param.orthantwise_end);
+            veccpy(w, d, n);
         }
 
         j = end;
@@ -586,6 +587,17 @@ int lbfgs(
             j = (j + 1) % m;        /* if (++j == m) j = 0; */
         }
 
+        /*
+            Constrain the search direction for orthant-wise updates.
+         */
+        if (param.orthantwise_c != 0.) {
+            for (i = param.orthantwise_start;i < param.orthantwise_end;++i) {
+                if (d[i] * w[i] <= 0) {
+                    d[i] = 0;
+                }
+            }
+        }
+
         /*
             Now the search direction d is ready. We try step = 1 first.
          */