diff --git a/src/MOLECULE/angle_charmm.h b/src/MOLECULE/angle_charmm.h
index 2a77ac7864..cc4095e90f 100644
--- a/src/MOLECULE/angle_charmm.h
+++ b/src/MOLECULE/angle_charmm.h
@@ -35,6 +35,7 @@ class AngleCharmm : 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, *theta0, *k_ub, *r_ub;