diff --git a/ceilometer/compute/virt/vmware/vsphere_operations.py b/ceilometer/compute/virt/vmware/vsphere_operations.py
index 2531e1af..ed5c2e02 100644
--- a/ceilometer/compute/virt/vmware/vsphere_operations.py
+++ b/ceilometer/compute/virt/vmware/vsphere_operations.py
@@ -206,7 +206,8 @@ class VsphereOperations(object):
         query_spec.intervalId = VC_REAL_TIME_SAMPLING_INTERVAL
         # We query all samples which are applicable over the specified duration
         samples_cnt = (int(duration / VC_REAL_TIME_SAMPLING_INTERVAL)
-                       if duration else 1)
+                       if duration and
+                       duration >= VC_REAL_TIME_SAMPLING_INTERVAL else 1)
         query_spec.maxSample = samples_cnt
 
         perf_manager = session.vim.service_content.perfManager