diff --git a/lib/client/gnt_debug.py b/lib/client/gnt_debug.py
index 228733b5d27b7ab02d0db59b1dc39d03db7d6bb7..5eb58a29fa91e9e5597f91134532cea8e9f81289 100644
--- a/lib/client/gnt_debug.py
+++ b/lib/client/gnt_debug.py
@@ -174,7 +174,8 @@ def TestAllocator(opts, args):
                                direction=opts.direction,
                                allocator=opts.iallocator,
                                evac_mode=opts.evac_mode,
-                               target_groups=target_groups)
+                               target_groups=target_groups,
+                               spindle_use=opts.spindle_use)
   result = SubmitOpCode(op, opts=opts)
   ToStdout("%s" % result)
   return 0
@@ -672,6 +673,8 @@ commands = {
                       utils.CommaJoin(constants.IALLOCATOR_NEVAC_MODES))),
      cli_option("--target-groups", help="Target groups for relocation",
                 default=[], action="append"),
+     cli_option("--spindle-use", help="How many spindles to use",
+                default=1, type="int"),
      DRY_RUN_OPT, PRIORITY_OPT,
      ],
     "{opts...} <instance>", "Executes a TestAllocator OpCode"),
diff --git a/lib/cmdlib.py b/lib/cmdlib.py
index cf2769e82e9bc3e443b46a35702e4064bb88b58e..3860d559d678a84ff8bac43d3f28f0c78fcffdc0 100644
--- a/lib/cmdlib.py
+++ b/lib/cmdlib.py
@@ -15295,6 +15295,7 @@ class LUTestAllocator(NoHooksLU):
                        nics=self.op.nics,
                        vcpus=self.op.vcpus,
                        hypervisor=self.op.hypervisor,
+                       spindle_use=self.op.spindle_use,
                        )
     elif self.op.mode == constants.IALLOCATOR_MODE_RELOC:
       ial = IAllocator(self.cfg, self.rpc,
diff --git a/lib/opcodes.py b/lib/opcodes.py
index aa7cce1e0ade0abcec689d9070d4e53eeb284baa..3243e0ea75024a519e3460d02ba9c60eda407c26 100644
--- a/lib/opcodes.py
+++ b/lib/opcodes.py
@@ -1853,6 +1853,7 @@ class OpTestAllocator(OpCode):
     ("evac_mode", None,
      ht.TOr(ht.TNone, ht.TElemOf(constants.IALLOCATOR_NEVAC_MODES)), None),
     ("target_groups", None, ht.TMaybeListOf(ht.TNonEmptyString), None),
+    ("spindle_use", 1, ht.TPositiveInt, None),
     ]