diff --git a/hw/block/fdc.c b/hw/block/fdc.c
index 7b7dd41296..cd29e27d8f 100644
--- a/hw/block/fdc.c
+++ b/hw/block/fdc.c
@@ -2695,7 +2695,10 @@ static void isabus_fdc_realize(DeviceState *dev, Error **errp)
     fdctrl->dma_chann = isa->dma;
     if (fdctrl->dma_chann != -1) {
         fdctrl->dma = isa_get_dma(isa_bus_from_device(isadev), isa->dma);
-        assert(fdctrl->dma);
+        if (!fdctrl->dma) {
+            error_setg(errp, "ISA controller does not support DMA");
+            return;
+        }
     }
 
     qdev_set_legacy_instance_id(dev, isa->iobase, 2);