diff --git a/net_func.cc b/net_func.cc
index aa92b9b3a..a2ce368d3 100644
--- a/net_func.cc
+++ b/net_func.cc
@@ -50,24 +50,6 @@ NetUserFunc::~NetUserFunc()
 {
 }
 
-ivl_variable_type_t NetUserFunc::data_type(unsigned port) const
-{
-      NetFuncDef*fdef = def_->func_def();
-
-	/* Port 0 is the return port. */
-      if (port == 0) {
-	    const NetNet*sig = fdef->return_sig();
-	    assert(sig);
-	    return sig->data_type();
-      }
-
-      port -= 1;
-      assert(port < fdef->port_count());
-      const NetNet*port_sig = fdef->port(port);
-
-      return port_sig->data_type();
-}
-
 unsigned NetUserFunc::port_width(unsigned port) const
 {
       NetFuncDef*fdef = def_->func_def();
diff --git a/netlist.h b/netlist.h
index ac6956db4..7fa85845a 100644
--- a/netlist.h
+++ b/netlist.h
@@ -1919,7 +1919,6 @@ class NetUserFunc  : public NetNode {
       NetUserFunc(NetScope*s, perm_string n, NetScope*def, NetEvWait*trigger__);
       ~NetUserFunc();
 
-      ivl_variable_type_t data_type(unsigned port) const;
       unsigned port_width(unsigned port) const;
 
       const NetScope* def() const;