diff --git a/rpcs3/Emu/Cell/lv2/sys_rsx.cpp b/rpcs3/Emu/Cell/lv2/sys_rsx.cpp
index c6bf5c09b0..45a7060960 100644
--- a/rpcs3/Emu/Cell/lv2/sys_rsx.cpp
+++ b/rpcs3/Emu/Cell/lv2/sys_rsx.cpp
@@ -186,13 +186,12 @@ s32 sys_rsx_context_iomap(u32 context_id, u32 io, u32 ea, u32 size, u64 flags)
 /*
  * lv2 SysCall 673 (0x2A1): sys_rsx_context_iounmap
  * @param context_id (IN): RSX context, E.g. 0x55555555 (in vsh.self)
- * @param a2 (IN): ?
  * @param io_addr (IN): IO address. E.g. 0x00600000 (Start page 6)
  * @param size (IN): Size to unmap in byte. E.g. 0x00200000
  */
-s32 sys_rsx_context_iounmap(u32 context_id, u32 io_addr, u32 a3, u32 size)
+s32 sys_rsx_context_iounmap(u32 context_id, u32 io_addr, u32 size)
 {
-	sys_rsx.warning("sys_rsx_context_iounmap(context_id=0x%x, io_addr=0x%x, a3=0x%x, size=0x%x)", context_id, io_addr, a3, size);
+	sys_rsx.warning("sys_rsx_context_iounmap(context_id=0x%x, io_addr=0x%x, size=0x%x)", context_id, io_addr, size);
 	if (RSXIOMem.UnmapAddress(io_addr, size))
 		return CELL_OK;
 	return CELL_EINVAL;
diff --git a/rpcs3/Emu/Cell/lv2/sys_rsx.h b/rpcs3/Emu/Cell/lv2/sys_rsx.h
index df71049351..0cbea30da7 100644
--- a/rpcs3/Emu/Cell/lv2/sys_rsx.h
+++ b/rpcs3/Emu/Cell/lv2/sys_rsx.h
@@ -114,7 +114,7 @@ s32 sys_rsx_memory_free(u32 mem_handle);
 s32 sys_rsx_context_allocate(vm::ptr<u32> context_id, vm::ptr<u64> lpar_dma_control, vm::ptr<u64> lpar_driver_info, vm::ptr<u64> lpar_reports, u64 mem_ctx, u64 system_mode);
 s32 sys_rsx_context_free(u32 context_id);
 s32 sys_rsx_context_iomap(u32 context_id, u32 io, u32 ea, u32 size, u64 flags);
-s32 sys_rsx_context_iounmap(u32 context_id, u32 a2, u32 io_addr, u32 size);
+s32 sys_rsx_context_iounmap(u32 context_id, u32 io_addr, u32 size);
 s32 sys_rsx_context_attribute(s32 context_id, u32 package_id, u64 a3, u64 a4, u64 a5, u64 a6);
 s32 sys_rsx_device_map(vm::ptr<u64> dev_addr, vm::ptr<u64> a2, u32 dev_id);
 s32 sys_rsx_device_unmap(u32 dev_id);