diff --git a/vpi/sys_icarus.c b/vpi/sys_icarus.c
index d2e1921d2..ecfdc5f02 100644
--- a/vpi/sys_icarus.c
+++ b/vpi/sys_icarus.c
@@ -42,18 +42,159 @@ static PLI_INT32 finish_and_return_calltf(PLI_BYTE8* name)
     return 0;
 }
 
+static PLI_INT32 task_not_implemented_compiletf(PLI_BYTE8* name)
+{
+      vpiHandle callh = vpi_handle(vpiSysTfCall, 0);
+
+      vpi_printf("%s:%d: SORRY: task %s() is not currently implemented.\n",
+                 vpi_get_str(vpiFile, callh), (int)vpi_get(vpiLineNo, callh),
+                 name);
+      vpi_control(vpiFinish, 1);
+      return 0;
+}
+
+static PLI_INT32 function_not_implemented_compiletf(PLI_BYTE8* name)
+{
+      vpiHandle callh = vpi_handle(vpiSysTfCall, 0);
+
+      vpi_printf("%s:%d: SORRY: function %s() is not currently implemented.\n",
+                 vpi_get_str(vpiFile, callh), (int)vpi_get(vpiLineNo, callh),
+                 name);
+      vpi_control(vpiFinish, 1);
+      return 0;
+}
+
 /*
  * Register the function with Verilog.
  */
 void sys_special_register(void)
 {
-    s_vpi_systf_data tf_data;
+      s_vpi_systf_data tf_data;
 
-    tf_data.type        = vpiSysTask;
-    tf_data.calltf      = finish_and_return_calltf;
-    tf_data.compiletf   = sys_one_numeric_arg_compiletf;
-    tf_data.sizetf      = 0;
-    tf_data.tfname      = "$finish_and_return";
-    tf_data.user_data   = "$finish_and_return";
-    vpi_register_systf(&tf_data);
+      tf_data.type        = vpiSysTask;
+      tf_data.calltf      = finish_and_return_calltf;
+      tf_data.compiletf   = sys_one_numeric_arg_compiletf;
+      tf_data.sizetf      = 0;
+      tf_data.tfname      = "$finish_and_return";
+      tf_data.user_data   = "$finish_and_return";
+      vpi_register_systf(&tf_data);
+
+	/* These tasks are not currently implemented. */
+      tf_data.type        = vpiSysTask;
+      tf_data.calltf      = 0;
+      tf_data.sizetf      = 0;
+      tf_data.compiletf   = task_not_implemented_compiletf;
+
+      tf_data.tfname      = "$fmonitor";
+      tf_data.user_data   = "$fmonitor";
+      vpi_register_systf(&tf_data);
+
+      tf_data.tfname      = "$fmonitorb";
+      tf_data.user_data   = "$fmonitorb";
+      vpi_register_systf(&tf_data);
+
+      tf_data.tfname      = "$fmonitoro";
+      tf_data.user_data   = "$fmonitoro";
+      vpi_register_systf(&tf_data);
+
+      tf_data.tfname      = "$fmonitorh";
+      tf_data.user_data   = "$fmonitorh";
+      vpi_register_systf(&tf_data);
+
+      tf_data.tfname      = "$async$and$array";
+      tf_data.user_data   = "$async$and$array";
+      vpi_register_systf(&tf_data);
+
+      tf_data.tfname      = "$async$nand$array";
+      tf_data.user_data   = "$async$nand$array";
+      vpi_register_systf(&tf_data);
+
+      tf_data.tfname      = "$async$or$array";
+      tf_data.user_data   = "$async$or$array";
+      vpi_register_systf(&tf_data);
+
+      tf_data.tfname      = "$async$nor$array";
+      tf_data.user_data   = "$async$nor$array";
+      vpi_register_systf(&tf_data);
+
+      tf_data.tfname      = "$async$and$plane";
+      tf_data.user_data   = "$async$and$plane";
+      vpi_register_systf(&tf_data);
+
+      tf_data.tfname      = "$async$nand$plane";
+      tf_data.user_data   = "$async$nand$plane";
+      vpi_register_systf(&tf_data);
+
+      tf_data.tfname      = "$async$or$plane";
+      tf_data.user_data   = "$async$or$plane";
+      vpi_register_systf(&tf_data);
+
+      tf_data.tfname      = "$async$nor$plane";
+      tf_data.user_data   = "$async$nor$plane";
+      vpi_register_systf(&tf_data);
+
+      tf_data.tfname      = "$sync$and$array";
+      tf_data.user_data   = "$sync$and$array";
+      vpi_register_systf(&tf_data);
+
+      tf_data.tfname      = "$sync$nand$array";
+      tf_data.user_data   = "$sync$nand$array";
+      vpi_register_systf(&tf_data);
+
+      tf_data.tfname      = "$sync$or$array";
+      tf_data.user_data   = "$sync$or$array";
+      vpi_register_systf(&tf_data);
+
+      tf_data.tfname      = "$sync$nor$array";
+      tf_data.user_data   = "$sync$nor$array";
+      vpi_register_systf(&tf_data);
+
+      tf_data.tfname      = "$sync$and$plane";
+      tf_data.user_data   = "$sync$and$plane";
+      vpi_register_systf(&tf_data);
+
+      tf_data.tfname      = "$sync$nand$plane";
+      tf_data.user_data   = "$sync$nand$plane";
+      vpi_register_systf(&tf_data);
+
+      tf_data.tfname      = "$sync$or$plane";
+      tf_data.user_data   = "$sync$or$plane";
+      vpi_register_systf(&tf_data);
+
+      tf_data.tfname      = "$sync$nor$plane";
+      tf_data.user_data   = "$sync$nor$plane";
+      vpi_register_systf(&tf_data);
+
+      tf_data.tfname      = "$q_initialize";
+      tf_data.user_data   = "$q_initialize";
+      vpi_register_systf(&tf_data);
+
+      tf_data.tfname      = "$q_add";
+      tf_data.user_data   = "$q_add";
+      vpi_register_systf(&tf_data);
+
+      tf_data.tfname      = "$q_remove";
+      tf_data.user_data   = "$q_remove";
+      vpi_register_systf(&tf_data);
+
+      tf_data.tfname      = "$q_full";
+      tf_data.user_data   = "$q_full";
+      vpi_register_systf(&tf_data);
+
+      tf_data.tfname      = "$q_exam";
+      tf_data.user_data   = "$q_exam";
+      vpi_register_systf(&tf_data);
+
+	/* These functions are not currently implemented. */
+      tf_data.compiletf   = function_not_implemented_compiletf;
+      tf_data.type = vpiSysFunc;
+      tf_data.sysfunctype = vpiIntFunc;
+
+      tf_data.tfname      = "$ferror";
+      tf_data.user_data   = "$ferror";
+      vpi_register_systf(&tf_data);
+
+      tf_data.tfname      = "$fread";
+      tf_data.user_data   = "$fread";
+      vpi_register_systf(&tf_data);
 }