diff --git a/src/emu/debug/debugcmd.cpp b/src/emu/debug/debugcmd.cpp
index 11f876d912f..cba9368dbf4 100644
--- a/src/emu/debug/debugcmd.cpp
+++ b/src/emu/debug/debugcmd.cpp
@@ -235,8 +235,8 @@ debugger_commands::debugger_commands(running_machine& machine, debugger_cpu& cpu
 
 	m_console.register_command("dasm",      CMDFLAG_NONE, 0, 3, 5, std::bind(&debugger_commands::execute_dasm, this, _1, _2, _3));
 
-	m_console.register_command("trace",     CMDFLAG_NONE, 0, 1, 3, std::bind(&debugger_commands::execute_trace, this, _1, _2, _3));
-	m_console.register_command("traceover", CMDFLAG_NONE, 0, 1, 3, std::bind(&debugger_commands::execute_traceover, this, _1, _2, _3));
+	m_console.register_command("trace",     CMDFLAG_NONE, 0, 1, 4, std::bind(&debugger_commands::execute_trace, this, _1, _2, _3));
+	m_console.register_command("traceover", CMDFLAG_NONE, 0, 1, 4, std::bind(&debugger_commands::execute_traceover, this, _1, _2, _3));
 	m_console.register_command("traceflush",CMDFLAG_NONE, 0, 0, 0, std::bind(&debugger_commands::execute_traceflush, this, _1, _2, _3));
 
 	m_console.register_command("history",   CMDFLAG_NONE, 0, 0, 2, std::bind(&debugger_commands::execute_history, this, _1, _2, _3));