diff --git a/tests/integration/targets/virtual_disk/tasks/01_supported.yml b/tests/integration/targets/virtual_disk/tasks/01_supported.yml
index 3164cf0e..8c05287c 100644
--- a/tests/integration/targets/virtual_disk/tasks/01_supported.yml
+++ b/tests/integration/targets/virtual_disk/tasks/01_supported.yml
@@ -37,9 +37,24 @@
       # Update: maybe `qemu-img convert -c` compress option is a problem
       mkfs.ext4 xlab-ci-test-VD.raw
       qemu-img convert -O qcow2 xlab-ci-test-VD.raw xlab-ci-test-VD.qcow2
-      # Empty vmdk image seems to be OK
-      # But non-empty image with ext4 filesystem is a problem.
-      qemu-img create -f vmdk xlab-ci-test-VD.vmdk 10M
+      # The .vmdk must not be completely empty either.
+      #
+      # It used to be built with a bare `qemu-img create -f vmdk ... 10M`, which produces a
+      # 65536-byte file with nothing allocated. On HyperCore 9.8.2.226476 that upload fails with
+      # HTTP 502 and this target cannot pass. Measured: the boundary is the FILE size, not the
+      # virtual size. A monolithicSparse vmdk whose file is 65536 bytes fails; 131072 bytes or more
+      # succeeds. 1M/10M/100M/400M virtual all produce a 65536-byte file and all fail, while 500M
+      # produces 131072 bytes and passes. HyperCore 9.7.6.226153 accepts every one of them, so this
+      # is new in 9.8.x. An issue has been filed with Scale Computing against the HyperCore product
+      # for the underlying defect; the change here only stops the test depending on the affected case.
+      #
+      # A few KiB of data is enough to cross that boundary. Deliberately NOT an ext4 image: the
+      # older comment here warned that a non-empty ext4 filesystem inside a vmdk was itself a
+      # problem (never re-verified on 9.5/9.6, so worth continuing to avoid), and this keeps the
+      # .vmdk independent of mkfs.ext4.
+      qemu-img create -f raw xlab-ci-test-VD-vmdk-src.raw 10M
+      dd if=/dev/urandom of=xlab-ci-test-VD-vmdk-src.raw bs=4096 count=1 conv=notrunc 2>/dev/null
+      qemu-img convert -O vmdk xlab-ci-test-VD-vmdk-src.raw xlab-ci-test-VD.vmdk
 
 # ----------------------------------Job------------------------------------------------------------------------
 - name: Upload virtual disk file .qcow2