diff --git a/dev_tools/run_linux_on_vm_userland.sh b/dev_tools/run_linux_on_vm_userland.sh
index 18d426a8b6..a95f2bfc46 100755
--- a/dev_tools/run_linux_on_vm_userland.sh
+++ b/dev_tools/run_linux_on_vm_userland.sh
@@ -42,7 +42,9 @@
 # passing tests with concurrent runs, the other CPUs ran none (a smoke check,
 # for the other CPUs running nothing at all). With more than
 # 4, the preempt test is skipped: it checks preemption with 8 CPU-bound
-# programs. Both need QEMU_SMP to start with the CPU count, or to have cpus=.
+# programs. With more than 1, the fork_hosted test is skipped: it is flaky
+# there (a fork bug, to be fixed). These need QEMU_SMP to start with the CPU
+# count, or to have cpus=.
 #
 # Usage: dev_tools/run_linux_on_vm_userland.sh [-t <test>]... [-r] [-v]
 #   -t   test to run, e.g. hello (repeatable; default: every test)
@@ -226,6 +228,13 @@ for t in "${tests[@]}"; do
         skipped=$((skipped + 1))
         continue
     fi
+    # TODO: run it again once the fork bug that makes it flaky with more
+    # than 1 CPU is fixed.
+    if [[ $t == fork_hosted && ${smp:-1} -gt 1 ]]; then
+        echo "SKIP  $t  (flaky with more than 1 CPU: see the header)"
+        skipped=$((skipped + 1))
+        continue
+    fi
     mkdir -p "$WORK/$t"
     cp "$USERLAND" "$WORK/$t/runner.elf"
     cp "$WORK/rootfs.tar" "$WORK/$t/rootfs.tar"