diff --git a/hw/rtc/m48t59-isa.c b/hw/rtc/m48t59-isa.c
index cae315e488..dc21fb10a5 100644
--- a/hw/rtc/m48t59-isa.c
+++ b/hw/rtc/m48t59-isa.c
@@ -58,31 +58,6 @@ static M48txxInfo m48txx_isa_info[] = {
     }
 };
 
-Nvram *m48t59_init_isa(ISABus *bus, uint32_t io_base, uint16_t size,
-                       int base_year, int model)
-{
-    ISADevice *isa_dev;
-    DeviceState *dev;
-    int i;
-
-    for (i = 0; i < ARRAY_SIZE(m48txx_isa_info); i++) {
-        if (m48txx_isa_info[i].size != size ||
-            m48txx_isa_info[i].model != model) {
-            continue;
-        }
-
-        isa_dev = isa_new(m48txx_isa_info[i].bus_name);
-        dev = DEVICE(isa_dev);
-        qdev_prop_set_uint32(dev, "iobase", io_base);
-        qdev_prop_set_int32(dev, "base-year", base_year);
-        isa_realize_and_unref(isa_dev, bus, &error_fatal);
-        return NVRAM(dev);
-    }
-
-    assert(false);
-    return NULL;
-}
-
 static uint32_t m48txx_isa_read(Nvram *obj, uint32_t addr)
 {
     M48txxISAState *d = M48TXX_ISA(obj);
diff --git a/include/hw/rtc/m48t59.h b/include/hw/rtc/m48t59.h
index 04abedf3b2..9defe578d1 100644
--- a/include/hw/rtc/m48t59.h
+++ b/include/hw/rtc/m48t59.h
@@ -47,8 +47,6 @@ struct NvramClass {
     void (*toggle_lock)(Nvram *obj, int lock);
 };
 
-Nvram *m48t59_init_isa(ISABus *bus, uint32_t io_base, uint16_t size,
-                       int base_year, int type);
 Nvram *m48t59_init(qemu_irq IRQ, hwaddr mem_base,
                    uint32_t io_base, uint16_t size, int base_year,
                    int type);