diff --git a/hw/application_fpga/Makefile b/hw/application_fpga/Makefile
index 447ff38..7e6a6b6 100644
--- a/hw/application_fpga/Makefile
+++ b/hw/application_fpga/Makefile
@@ -205,6 +205,8 @@ simfirmware.elf: $(FIRMWARE_OBJS) $(P)/fw/tk1/firmware.lds
 
 qemu_firmware.elf: CFLAGS += -DQEMU_DEBUG
 qemu_firmware.elf: ASFLAGS += -DQEMU_DEBUG
+qemu_firmware.elf: CFLAGS += -DQEMU_SYSCALL
+qemu_firmware.elf: ASFLAGS += -DQEMU_SYSCALL
 qemu_firmware.elf: firmware.elf
 	mv firmware.elf qemu_firmware.elf
 
diff --git a/hw/application_fpga/fw/tk1/start.S b/hw/application_fpga/fw/tk1/start.S
index cdfb39f..f947e1e 100644
--- a/hw/application_fpga/fw/tk1/start.S
+++ b/hw/application_fpga/fw/tk1/start.S
@@ -5,7 +5,7 @@
 
 #include <tkey/tk1_mem.h>
 
-#ifdef QEMU_DEBUG
+#ifdef QEMU_SYSCALL
 
 #define picorv32_retirq_insn(...) \
 	mv ra, x3; \
diff --git a/hw/application_fpga/fw/tk1/syscall_enable.S b/hw/application_fpga/fw/tk1/syscall_enable.S
index 58cc62a..2060ddb 100644
--- a/hw/application_fpga/fw/tk1/syscall_enable.S
+++ b/hw/application_fpga/fw/tk1/syscall_enable.S
@@ -1,4 +1,4 @@
-#ifdef QEMU_DEBUG
+#ifdef QEMU_SYSCALL
 
 #define picorv32_maskirq_insn(...)