diff --git a/src/systemc/core/sc_port.cc b/src/systemc/core/sc_port.cc
index 46a295b..0f981ea 100644
--- a/src/systemc/core/sc_port.cc
+++ b/src/systemc/core/sc_port.cc
@@ -39,4 +39,16 @@
     warn("%s not implemented.\n", func);
 }
 
+void
+sc_port_base::bind(sc_interface &)
+{
+    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
+}
+
+void
+sc_port_base::bind(sc_port_base &)
+{
+    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
+}
+
 } // namespace sc_core
diff --git a/src/systemc/ext/core/sc_port.hh b/src/systemc/ext/core/sc_port.hh
index dfcae95..6f7c676 100644
--- a/src/systemc/ext/core/sc_port.hh
+++ b/src/systemc/ext/core/sc_port.hh
@@ -52,6 +52,11 @@
     {}
 
     void warn_unimpl(const char *func) const;
+
+  protected:
+    // Implementation defined, but depended on by the tests.
+    void bind(sc_interface &);
+    void bind(sc_port_base &);
 };
 
 template <class IF>