diff --git a/Analyser/Static/Commodore/StaticAnalyser.cpp b/Analyser/Static/Commodore/StaticAnalyser.cpp
index 0a7a55e3e..90bd0b624 100644
--- a/Analyser/Static/Commodore/StaticAnalyser.cpp
+++ b/Analyser/Static/Commodore/StaticAnalyser.cpp
@@ -94,6 +94,7 @@ Analyser::Static::TargetList Analyser::Static::Commodore::GetTargets(const Media
 		switch(files.front().starting_address) {
 			default:
 				LOG("Unrecognised loading address for Commodore program: " << PADHEX(4) <<  files.front().starting_address);
+				[[fallthrough]];
 			case 0x1001:
 				memory_model = Target::MemoryModel::Unexpanded;
 			break;
diff --git a/Components/5380/ncr5380.cpp b/Components/5380/ncr5380.cpp
index 3fb2a9514..52f3d4570 100644
--- a/Components/5380/ncr5380.cpp
+++ b/Components/5380/ncr5380.cpp
@@ -263,6 +263,7 @@ void NCR5380::scsi_bus_did_change(SCSI::Bus *, SCSI::BusState new_state, double
 		case ExecutionState::WaitingForBusy:
 			if(!(new_state & SCSI::Line::Busy) || time_since_change < SCSI::DeskewDelay) return;
 			state_ = ExecutionState::WatchingBusy;
+			[[fallthrough]];
 
 		case ExecutionState::WatchingBusy:
 			if(!(new_state & SCSI::Line::Busy)) {
diff --git a/Components/DiskII/IWM.cpp b/Components/DiskII/IWM.cpp
index 3a21a8fab..17438d2db 100644
--- a/Components/DiskII/IWM.cpp
+++ b/Components/DiskII/IWM.cpp
@@ -307,8 +307,8 @@ void IWM::run_for(const Cycles cycles) {
 			} else {
 				shift_register_ = sense();
 			}
+			[[fallthrough]];
 
-		/* Deliberate fallthrough. */
 		default:
 			if(drive_is_rotating_[active_drive_]) drives_[active_drive_]->run_for(cycles);
 		break;
diff --git a/Machines/Atari/ST/AtariST.cpp b/Machines/Atari/ST/AtariST.cpp
index 55dd45d3b..6ddf2dfce 100644
--- a/Machines/Atari/ST/AtariST.cpp
+++ b/Machines/Atari/ST/AtariST.cpp
@@ -237,6 +237,7 @@ class ConcreteMachine:
 						memory = rom_.data();
 						break;
 					}
+					[[fallthrough]];
 				case BusDevice::RAM:
 					memory = ram_.data();
 				break;
diff --git a/Machines/ColecoVision/ColecoVision.cpp b/Machines/ColecoVision/ColecoVision.cpp
index 0de8f56d0..c8ebd9074 100644
--- a/Machines/ColecoVision/ColecoVision.cpp
+++ b/Machines/ColecoVision/ColecoVision.cpp
@@ -224,6 +224,7 @@ class ConcreteMachine:
 				switch(cycle.operation) {
 					case CPU::Z80::PartialMachineCycle::ReadOpcode:
 						if(!address) pc_zero_accesses_++;
+						[[fallthrough]];
 					case CPU::Z80::PartialMachineCycle::Read:
 						if(address < 0x2000) {
 							if(super_game_module_.replace_bios) {
diff --git a/Machines/Electron/Electron.cpp b/Machines/Electron/Electron.cpp
index 1bf54f0f8..53fb9b028 100644
--- a/Machines/Electron/Electron.cpp
+++ b/Machines/Electron/Electron.cpp
@@ -215,7 +215,8 @@ class ConcreteMachine:
 								activity_observer_->set_led_status(caps_led, caps_led_state_);
 						}
 
-					// deliberate fallthrough; fe07 contains the display mode.
+						[[fallthrough]];	// fe07 contains the display mode.
+
 
 					case 0xfe02: case 0xfe03:
 					case 0xfe08: case 0xfe09: case 0xfe0a: case 0xfe0b:
diff --git a/Machines/MSX/MSX.cpp b/Machines/MSX/MSX.cpp
index febf9dbba..30695d0e9 100644
--- a/Machines/MSX/MSX.cpp
+++ b/Machines/MSX/MSX.cpp
@@ -492,6 +492,8 @@ class ConcreteMachine:
 							performed_unmapped_access_ = true;
 						}
 						pc_address_ = address;	// This is retained so as to be able to name the source of an access to cartridge handlers.
+						[[fallthrough]];
+
 					case CPU::Z80::PartialMachineCycle::Read:
 						if(read_pointers_[address >> 13]) {
 							*cycle.value = read_pointers_[address >> 13][address & 8191];
diff --git a/Machines/ZX8081/ZX8081.cpp b/Machines/ZX8081/ZX8081.cpp
index 6108ef28a..e998da86f 100644
--- a/Machines/ZX8081/ZX8081.cpp
+++ b/Machines/ZX8081/ZX8081.cpp
@@ -269,6 +269,7 @@ template<bool is_zx81> class ConcreteMachine:
 						tape_player_.set_motor_control((address >= automatic_tape_motor_start_address_) && (address < automatic_tape_motor_end_address_));
 					}
 					is_opcode_read = true;
+					[[fallthrough]];
 
 				case CPU::Z80::PartialMachineCycle::Read:
 					if(address < ram_base_) {
diff --git a/Processors/Z80/Implementation/Z80Implementation.hpp b/Processors/Z80/Implementation/Z80Implementation.hpp
index 2685e907e..677d55d69 100644
--- a/Processors/Z80/Implementation/Z80Implementation.hpp
+++ b/Processors/Z80/Implementation/Z80Implementation.hpp
@@ -833,7 +833,8 @@ template <	class T,
 // MARK: - Special-case Flow
 
 				case MicroOp::BeginIRQMode0:
-					pc_increment_ = 0;			// deliberate fallthrough
+					pc_increment_ = 0;
+					[[fallthrough]];
 				case MicroOp::BeginIRQ:
 					iff2_ = iff1_ = false;
 					request_status_ &= ~Interrupt::IRQ;