diff --git a/tests/pkg_jsmn/simple.c b/tests/pkg_jsmn/simple.c
index 2e3a2b4209..6360b12101 100644
--- a/tests/pkg_jsmn/simple.c
+++ b/tests/pkg_jsmn/simple.c
@@ -29,12 +29,9 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include "kernel_defines.h"  /* for ARRAY_SIZE macro */
 #include "jsmn.h"
 
-#ifndef ARRAY_SIZE
-#define ARRAY_SIZE(a) (sizeof(a)/sizeof(*a))
-#endif
-
 /*
  * A small example of jsmn parsing when JSON structure is known and number of
  * tokens is predictable.