diff --git a/NEWS b/NEWS
index f960c77bfebe5c125c38c10674227bb5546eefd3..1a24638494497a056167631e5244bb83d6110c19 100644
--- a/NEWS
+++ b/NEWS
@@ -237,6 +237,7 @@ documents those changes that are of interest to users and administrators.
     TopologyParam options No*InAddrAny.
  -- Cray - Better robustness when dealing with the aeld interface.
  -- job_submit.lua - add array_inx value for job arrays.
+ -- Perlapi - Remove unneeded/undefined mutex.
 
 * Changes in Slurm 15.08.11
 ===========================
diff --git a/contribs/perlapi/libslurm/perl/job.c b/contribs/perlapi/libslurm/perl/job.c
index 5247d5cda47b5e59585f92f760db3489517f1711..ce6de5940719c0bb5412967ac8157db31a02c3d8 100644
--- a/contribs/perlapi/libslurm/perl/job.c
+++ b/contribs/perlapi/libslurm/perl/job.c
@@ -38,7 +38,6 @@ static uint32_t _threads_per_core(char *host)
 	if (!job_node_ptr || !host)
 		return threads;
 
-	slurm_mutex_lock(&job_node_info_lock);
 	for (i = 0; i < job_node_ptr->record_count; i++) {
 		if (job_node_ptr->node_array[i].name &&
 		    !strcmp(host, job_node_ptr->node_array[i].name)) {
@@ -46,7 +45,7 @@ static uint32_t _threads_per_core(char *host)
 			break;
 		}
 	}
-	slurm_mutex_unlock(&job_node_info_lock);
+
 	return threads;
 }