diff --git a/tests/xtimer_usleep_until/Makefile b/tests/xtimer_usleep_until/Makefile
index fad1c5aea6..73c8e4b897 100644
--- a/tests/xtimer_usleep_until/Makefile
+++ b/tests/xtimer_usleep_until/Makefile
@@ -4,6 +4,8 @@ include ../Makefile.tests_common
 BOARD ?= native
 RIOTBASE ?= $(CURDIR)/../..
 
+BOARD_INSUFFICIENT_MEMORY := chronos
+
 FEATURES_REQUIRED += periph_timer
 USEMODULE += xtimer
 
diff --git a/tests/xtimer_usleep_until/main.c b/tests/xtimer_usleep_until/main.c
index 2430c89243..bea4f407a7 100644
--- a/tests/xtimer_usleep_until/main.c
+++ b/tests/xtimer_usleep_until/main.c
@@ -22,9 +22,9 @@
 #include "xtimer.h"
 #include "periph_conf.h"
 
-#define N 1000
+#define NUMOF 1000
 
-uint32_t res[N];
+uint32_t res[NUMOF];
 
 int main(void)
 {
@@ -32,7 +32,7 @@ int main(void)
 
     uint32_t interval = 1000;
 
-    for (int i = 0; i < N; i++) {
+    for (int i = 0; i < NUMOF; i++) {
         printf("Testing interval %u...\n", (unsigned)interval);
         uint32_t last_wakeup = xtimer_now();
         uint32_t before = last_wakeup;
@@ -42,7 +42,7 @@ int main(void)
         interval -= 1;
     }
 
-    for (int i = 0; i < N; i++) {
+    for (int i = 0; i < NUMOF; i++) {
         printf("%4d diff=%i\n", i, (int)res[i]);
     }