diff --git a/src/DIPOLE/angle_dipole.h b/src/DIPOLE/angle_dipole.h
index 2e55722673..de0f958f98 100644
--- a/src/DIPOLE/angle_dipole.h
+++ b/src/DIPOLE/angle_dipole.h
@@ -36,6 +36,7 @@ class AngleDipole : public Angle {
   void read_restart(FILE *) override;
   void write_data(FILE *) override;
   double single(int, int, int, int) override;
+  void *extract(const char *, int &) override;
 
  protected:
   double *k, *gamma0;