diff --git a/src/devices/cpu/z80/nsc800.cpp b/src/devices/cpu/z80/nsc800.cpp
index 672d019a0c7..d94734527e7 100644
--- a/src/devices/cpu/z80/nsc800.cpp
+++ b/src/devices/cpu/z80/nsc800.cpp
@@ -47,9 +47,14 @@ void nsc800_device::device_reset()
 //-------------------------------------------------
 //  execute
 //-------------------------------------------------
-
-void nsc800_device::do_op()
+void nsc800_device::execute_run()
 {
+	if (m_wait_state)
+	{
+		m_icount = 0; // stalled
+		return;
+	}
+
 	#include "cpu/z80/ncs800.hxx"
 }
 
diff --git a/src/devices/cpu/z80/nsc800.h b/src/devices/cpu/z80/nsc800.h
index c37179fa700..aa05d2adf51 100644
--- a/src/devices/cpu/z80/nsc800.h
+++ b/src/devices/cpu/z80/nsc800.h
@@ -26,9 +26,9 @@ protected:
 	virtual void device_reset() override ATTR_COLD;
 
 	// device_execute_interface implementation
+	virtual void execute_run() override;
 	virtual void execute_set_input(int inputnum, int state) override;
 
-	virtual void do_op() override;
 	u8 m_nsc800_irq_state[3]; // state of NSC800 restart interrupts A, B, C
 };
 
diff --git a/src/devices/cpu/z80/r800.cpp b/src/devices/cpu/z80/r800.cpp
index 6a68b9e3d07..69b28fd6ac5 100644
--- a/src/devices/cpu/z80/r800.cpp
+++ b/src/devices/cpu/z80/r800.cpp
@@ -97,7 +97,13 @@ void r800_device::muluw(u16 value)
 	set_f((F & (HF|NF)) | z | c);
 }
 
-void r800_device::do_op()
+void r800_device::execute_run()
 {
+	if (m_wait_state)
+	{
+		m_icount = 0; // stalled
+		return;
+	}
+
 	#include "cpu/z80/r800.hxx"
 }
diff --git a/src/devices/cpu/z80/r800.h b/src/devices/cpu/z80/r800.h
index 69f8a922738..967ed29417d 100644
--- a/src/devices/cpu/z80/r800.h
+++ b/src/devices/cpu/z80/r800.h
@@ -33,6 +33,7 @@ protected:
 	// device_execute_interface overrides
 	virtual u64 execute_clocks_to_cycles(u64 clocks) const noexcept override { return (clocks + 4 - 1) / 4; }
 	virtual u64 execute_cycles_to_clocks(u64 cycles) const noexcept override { return (cycles * 4); }
+	virtual void execute_run() override;
 
 	// device_disasm_interface implementation
 	virtual std::unique_ptr<util::disasm_interface> create_disassembler() override;
@@ -40,8 +41,6 @@ protected:
 	u8 r800_sll(u8 value);
 	void mulub(u8 value);
 	void muluw(u16 value);
-
-	virtual void do_op() override;
 };
 
 // device type declaration
diff --git a/src/devices/cpu/z80/z80.cpp b/src/devices/cpu/z80/z80.cpp
index dec4cfbbd9a..99601d7860b 100644
--- a/src/devices/cpu/z80/z80.cpp
+++ b/src/devices/cpu/z80/z80.cpp
@@ -699,11 +699,6 @@ void z80_device::device_reset()
 	m_iff2 = 0;
 }
 
-void z80_device::do_op()
-{
-	#include "cpu/z80/z80.hxx"
-}
-
 /****************************************************************************
  * Execute 'cycles' T-states.
  ****************************************************************************/
@@ -715,10 +710,7 @@ void z80_device::execute_run()
 		return;
 	}
 
-	while (m_icount > 0)
-	{
-		do_op();
-	}
+	#include "cpu/z80/z80.hxx"
 }
 
 void z80_device::execute_set_input(int inputnum, int state)
diff --git a/src/devices/cpu/z80/z80.h b/src/devices/cpu/z80/z80.h
index eadaae4ba07..3a4c926299c 100644
--- a/src/devices/cpu/z80/z80.h
+++ b/src/devices/cpu/z80/z80.h
@@ -121,8 +121,6 @@ protected:
 	void set_f(u8 f);
 	void block_io_interrupted_flags();
 
-	virtual void do_op();
-
 	virtual u8 data_read(u16 addr);
 	virtual void data_write(u16 addr, u8 value);
 	virtual u8 stack_read(u16 addr) { return data_read(addr); }
diff --git a/src/devices/cpu/z80/z80.lst b/src/devices/cpu/z80/z80.lst
index 567e9b34940..3a2efed57f2 100644
--- a/src/devices/cpu/z80/z80.lst
+++ b/src/devices/cpu/z80/z80.lst
@@ -679,7 +679,7 @@ ffff
 		}
 		if (m_icount > 0)
 			m_icount = 0;
-		return;
+		goto leave;
 	} else if (m_busack_state) {
 		m_busack_state = 0;
 		m_busack_cb(0);
diff --git a/src/devices/cpu/z80/z80make.py b/src/devices/cpu/z80/z80make.py
index 4532c3d2fe2..cba4f6e344e 100644
--- a/src/devices/cpu/z80/z80make.py
+++ b/src/devices/cpu/z80/z80make.py
@@ -74,7 +74,7 @@ class Opcode:
                 to_step = "0x%s" % (hex(256 + step)[3:])
                 il.print("if (m_icount <= 0) {", f)
                 il.print("	m_ref = (m_ref & 0xffff00) | %s;" % (to_step), f)
-                il.print("	return;", f)
+                il.print("	goto leave;", f)
                 il.print("}", f)
                 il.print("[[fallthrough]];", f)
                 print("\t\tcase %s:" % (to_step), file=f)
@@ -92,7 +92,7 @@ class Opcode:
                 step += 1
                 to_step = "0x%s" % (hex(256 + step)[3:])
                 il.print("		m_ref = (m_ref & 0xffff00) | %s;" % (to_step), f)
-                il.print("	return;", f)
+                il.print("	goto leave;", f)
                 il.print("}", f)
                 il.print("[[fallthrough]];", f)
                 print("\t\tcase %s:" % (to_step), file=f)
@@ -251,6 +251,7 @@ class OpcodeList:
         print("", file=f)
         print("m_ref = 0xffff00;", file=f)
         print("goto rop;", file=f)
+        print("leave: ;", file=f)
 
 def main(argv):
     if len(argv) != 3 and len(argv) != 4:
diff --git a/src/devices/cpu/z80/z80n.cpp b/src/devices/cpu/z80/z80n.cpp
index 4acc97c715f..4398586ed70 100644
--- a/src/devices/cpu/z80/z80n.cpp
+++ b/src/devices/cpu/z80/z80n.cpp
@@ -31,8 +31,14 @@ z80n_device::z80n_device(const machine_config &mconfig, const char *tag, device_
 {
 }
 
-void z80n_device::do_op()
+void z80n_device::execute_run()
 {
+	if (m_wait_state)
+	{
+		m_icount = 0; // stalled
+		return;
+	}
+
 	#include "cpu/z80/z80n.hxx"
 }
 
diff --git a/src/devices/cpu/z80/z80n.h b/src/devices/cpu/z80/z80n.h
index a7db99722a9..8198412074c 100644
--- a/src/devices/cpu/z80/z80n.h
+++ b/src/devices/cpu/z80/z80n.h
@@ -26,7 +26,8 @@ protected:
 	virtual void device_start() override ATTR_COLD;
 	virtual void device_reset() override ATTR_COLD;
 
-	virtual void do_op() override;
+	// device_execute_interface implementation
+	virtual void execute_run() override;
 
 	devcb_write8 m_out_retn_seen_cb;
 	devcb_read8 m_in_nextreg_cb;