--- a/src/ov-scalar.h
+++ b/src/ov-scalar.h
@@ -64,12 +64,12 @@
 
   ~octave_scalar (void) { }
 
-  octave_value *clone (void) const { return new octave_scalar (*this); }
+  octave_base_value *clone (void) const { return new octave_scalar (*this); }
 
   // We return an octave_matrix here instead of an octave_scalar so
   // that in expressions like A(2,2,2) = 2 (for A previously
   // undefined), A will be empty instead of a 1x1 object.
-  octave_value *empty_clone (void) const { return new octave_matrix (); }
+  octave_base_value *empty_clone (void) const { return new octave_matrix (); }
 
   octave_value do_index_op (const octave_value_list& idx, int resize_ok);