diff --git a/source/blender/blenlib/BLI_task.h b/source/blender/blenlib/BLI_task.h
index 81649c469f6..15de7af45d6 100644
--- a/source/blender/blenlib/BLI_task.h
+++ b/source/blender/blenlib/BLI_task.h
@@ -120,11 +120,6 @@ bool BLI_task_pool_current_canceled(TaskPool *pool);
  */
 void *BLI_task_pool_user_data(TaskPool *pool);
 
-/**
- * Optional mutex to use from run function.
- */
-ThreadMutex *BLI_task_pool_user_mutex(TaskPool *pool);
-
 /** \} */
 
 /* -------------------------------------------------------------------- */
diff --git a/source/blender/blenlib/intern/task_pool.cc b/source/blender/blenlib/intern/task_pool.cc
index e9063b1d185..c45188cafe5 100644
--- a/source/blender/blenlib/intern/task_pool.cc
+++ b/source/blender/blenlib/intern/task_pool.cc
@@ -158,7 +158,6 @@ struct TaskPool {
   TaskPoolType type;
   bool use_threads;
 
-  ThreadMutex user_mutex;
   void *userdata;
 
 #ifdef WITH_TBB
@@ -185,8 +184,6 @@ struct TaskPool {
       this->type = TASK_POOL_TBB;
     }
 
-    BLI_mutex_init(&this->user_mutex);
-
     switch (this->type) {
       case TASK_POOL_TBB:
       case TASK_POOL_TBB_SUSPENDED:
@@ -229,8 +226,6 @@ struct TaskPool {
         break;
       }
     }
-
-    BLI_mutex_end(&this->user_mutex);
   }
 
   TaskPool(TaskPool &&other) = delete;
@@ -552,8 +547,3 @@ void *BLI_task_pool_user_data(TaskPool *pool)
 {
   return pool->userdata;
 }
-
-ThreadMutex *BLI_task_pool_user_mutex(TaskPool *pool)
-{
-  return &pool->user_mutex;
-}