diff --git a/src/emu/debug/debugcpu.cpp b/src/emu/debug/debugcpu.cpp
index 3b765d79cc2..962a8e025cd 100644
--- a/src/emu/debug/debugcpu.cpp
+++ b/src/emu/debug/debugcpu.cpp
@@ -987,7 +987,6 @@ u64 debugger_cpu::expression_read_memory(void *param, const char *name, expressi
 			break;
 		}
 
-		case EXPSPACE_OPCODE:
 		case EXPSPACE_RAMWRITE:
 		{
 			device_t *device = nullptr;
@@ -1008,6 +1007,26 @@ u64 debugger_cpu::expression_read_memory(void *param, const char *name, expressi
 			break;
 		}
 
+		case EXPSPACE_OPCODE:
+		{
+			device_t *device = nullptr;
+			device_memory_interface *memory;
+
+			if (name != nullptr)
+				device = expression_get_device(name);
+			if (device == nullptr || !device->interface(memory))
+			{
+				device = get_visible_cpu();
+				memory = &device->memory();
+			}
+			if (!with_se) {
+				auto dis = m_machine.disable_side_effect();
+				return expression_read_program_direct(memory->space(AS_DECRYPTED_OPCODES), (spacenum == EXPSPACE_OPCODE), address, size);
+			} else
+				return expression_read_program_direct(memory->space(AS_DECRYPTED_OPCODES), (spacenum == EXPSPACE_OPCODE), address, size);
+			break;
+		}	
+
 		case EXPSPACE_REGION:
 			if (name == nullptr)
 				break;
@@ -1179,7 +1198,6 @@ void debugger_cpu::expression_write_memory(void *param, const char *name, expres
 			}
 			break;
 
-		case EXPSPACE_OPCODE:
 		case EXPSPACE_RAMWRITE:
 			if (name != nullptr)
 				device = expression_get_device(name);
@@ -1195,6 +1213,21 @@ void debugger_cpu::expression_write_memory(void *param, const char *name, expres
 				expression_write_program_direct(memory->space(AS_PROGRAM), (spacenum == EXPSPACE_OPCODE), address, size, data);
 			break;
 
+		case EXPSPACE_OPCODE:
+			if (name != nullptr)
+				device = expression_get_device(name);
+			if (device == nullptr || !device->interface(memory))
+			{
+				device = get_visible_cpu();
+				memory = &device->memory();
+			}
+			if (!with_se) {
+				auto dis = m_machine.disable_side_effect();
+				expression_write_program_direct(memory->space(AS_DECRYPTED_OPCODES), (spacenum == EXPSPACE_OPCODE), address, size, data);
+			} else
+				expression_write_program_direct(memory->space(AS_DECRYPTED_OPCODES), (spacenum == EXPSPACE_OPCODE), address, size, data);
+			break;
+
 		case EXPSPACE_REGION:
 			if (name == nullptr)
 				break;
@@ -1367,7 +1400,6 @@ expression_error::error_code debugger_cpu::expression_validate(void *param, cons
 			return expression_error::NO_SUCH_MEMORY_SPACE;
 		break;
 
-	case EXPSPACE_OPCODE:
 	case EXPSPACE_RAMWRITE:
 		if (name)
 		{
@@ -1381,6 +1413,19 @@ expression_error::error_code debugger_cpu::expression_validate(void *param, cons
 			return expression_error::NO_SUCH_MEMORY_SPACE;
 		break;
 
+	case EXPSPACE_OPCODE:
+		if (name)
+		{
+			device = expression_get_device(name);
+			if (device == nullptr || !device->interface(memory))
+				return expression_error::INVALID_MEMORY_NAME;
+		}
+		if (!device)
+			device = get_visible_cpu();
+		if (!device->interface(memory) || !memory->has_space(AS_DECRYPTED_OPCODES))
+			return expression_error::NO_SUCH_MEMORY_SPACE;
+		break;
+
 	case EXPSPACE_REGION:
 		if (!name)
 			return expression_error::MISSING_MEMORY_NAME;