diff --git a/src/disk/mo.c b/src/disk/mo.c
index 44f68effa..ed1ab2472 100644
--- a/src/disk/mo.c
+++ b/src/disk/mo.c
@@ -951,6 +951,8 @@ mo_blocks(mo_t *dev, int32_t *len, UNUSED(int first_batch), int out)
         if (out) {
             if (fwrite(dev->buffer + (i * dev->drv->sector_size), 1, dev->drv->sector_size, dev->drv->fp) != dev->drv->sector_size)
                 fatal("mo_blocks(): Error writing data\n");
+
+            fflush(dev->drv->fp);
         } else {
             if (fread(dev->buffer + (i * dev->drv->sector_size), 1, dev->drv->sector_size, dev->drv->fp) != dev->drv->sector_size)
                 fatal("mo_blocks(): Error reading data\n");
@@ -1069,6 +1071,8 @@ mo_erase(mo_t *dev)
         fwrite(dev->buffer, 1, dev->drv->sector_size, dev->drv->fp);
     }
 
+    fflush(dev->drv->fp);
+
     mo_log("MO %i: Erased %i bytes of blocks...\n", dev->id, i * dev->drv->sector_size);
 
     dev->sector_pos += i;
diff --git a/src/disk/zip.c b/src/disk/zip.c
index 764dc1f53..a948cab2f 100644
--- a/src/disk/zip.c
+++ b/src/disk/zip.c
@@ -1134,6 +1134,8 @@ zip_blocks(zip_t *dev, int32_t *len, UNUSED(int first_batch), int out)
         if (out) {
             if (fwrite(dev->buffer + (i << 9), 1, 512, dev->drv->fp) != 512)
                 fatal("zip_blocks(): Error writing data\n");
+
+            fflush(dev->drv->fp);
         } else {
             if (fread(dev->buffer + (i << 9), 1, 512, dev->drv->fp) != 512)
                 fatal("zip_blocks(): Error reading data\n");
@@ -2125,6 +2127,8 @@ zip_phase_data_out(scsi_common_t *sc)
                 if (fwrite(dev->buffer, 1, 512, dev->drv->fp) != 512)
                     fatal("zip_phase_data_out(): Error writing data\n");
             }
+
+            fflush(dev->drv->fp);
             break;
         case GPCMD_MODE_SELECT_6:
         case GPCMD_MODE_SELECT_10: