diff --git a/src/helpers.h b/src/helpers.h
index 9d844f39..9cdbb076 100644
--- a/src/helpers.h
+++ b/src/helpers.h
@@ -14,6 +14,7 @@
  *  See the License for the specific language governing permissions and
  *  limitations under the License.
  ********************************************************************************/
+#include <sys/types.h>
 
 #include "os.h"
 #include "cx.h"