diff --git a/dask_jobqueue/lsf.py b/dask_jobqueue/lsf.py
index 5d508897..ccc6ae5a 100644
--- a/dask_jobqueue/lsf.py
+++ b/dask_jobqueue/lsf.py
@@ -88,6 +88,10 @@ def __init__(self, queue=None, project=None, ncpus=None, mem=None, walltime=None
             logger.info("ncpus specification for LSF not set, initializing it to %s" % ncpus)
         if ncpus is not None:
             header_lines.append('#BSUB -n %s' % ncpus)
+            if ncpus > 1:
+                # span[hosts=1] _might_ affect queue waiting
+                # time, and is not required if ncpus==1
+                header_lines.append('#BSUB -R "span[hosts=1]"')
         if mem is None:
             # Compute default memory specifications
             mem = self.worker_memory