diff --git a/bsp/efm32/rtconfig.h b/bsp/efm32/rtconfig.h
index 4ee9bf1a8e..040f07fa02 100644
--- a/bsp/efm32/rtconfig.h
+++ b/bsp/efm32/rtconfig.h
@@ -213,6 +213,7 @@
 /* SECTION: Runtime library */
 // #define RT_USING_NOLIBC
 // #define RT_USING_NEWLIB
+#define RT_LIBC_USING_TIME
 
 /* SECTION: Console options */
 #define RT_USING_CONSOLE