diff --git a/test/datatype/position.c b/test/datatype/position.c
index b96ed900f5..008a8e14b4 100644
--- a/test/datatype/position.c
+++ b/test/datatype/position.c
@@ -11,6 +11,7 @@
  */
 
 #include "ompi_config.h"
+#include <string.h>
 #include "ompi/datatype/convertor.h"
 #include "ompi/datatype/datatype.h"
 #include "opal/util/output.h"