diff --git a/src/operator/random/shuffle_op.cc b/src/operator/random/shuffle_op.cc
index 1bd70b1f323a..5b4d9c74766c 100644
--- a/src/operator/random/shuffle_op.cc
+++ b/src/operator/random/shuffle_op.cc
@@ -33,6 +33,7 @@
 #include <vector>
 #include <cstring>
 #ifdef USE_GNU_PARALLEL_SHUFFLE
+  #include <unistd.h>
   #include <parallel/algorithm>
 #endif
 #include "../elemwise_op_common.h"