diff --git a/src/colvarcomp_torchann.cpp b/src/colvarcomp_torchann.cpp
index be36bdadd..a776c0fe6 100644
--- a/src/colvarcomp_torchann.cpp
+++ b/src/colvarcomp_torchann.cpp
@@ -219,4 +219,8 @@ int colvar::torchANN::init(std::string const &conf) {
 
 }
 
+void colvar::torchANN::calc_value()
+{
+}
+
 #endif
diff --git a/src/colvarcomp_torchann.h b/src/colvarcomp_torchann.h
index 670688be9..216279e67 100644
--- a/src/colvarcomp_torchann.h
+++ b/src/colvarcomp_torchann.h
@@ -56,6 +56,7 @@ class colvar::torchANN
     torchANN();
     virtual ~torchANN();
     virtual int init(std::string const &conf);
+    virtual void calc_value();
 };
 #endif // COLVARS_TORCH checking