diff --git a/os/nil/ports/AVR/nilcore.h b/os/nil/ports/AVR/nilcore.h
index 28d06ce1e..3da48c262 100644
--- a/os/nil/ports/AVR/nilcore.h
+++ b/os/nil/ports/AVR/nilcore.h
@@ -122,15 +122,6 @@
    asm module.*/
 #if !defined(_FROM_ASM_)
 
-/**
- * @brief   Type of system time.
- */
-#if (NIL_CFG_ST_RESOLUTION == 32) || defined(__DOXYGEN__)
-typedef uint32_t systime_t;
-#else
-typedef uint16_t systime_t;
-#endif
-
 /**
  * @brief   Type of stack and memory alignment enforcement.
  */
diff --git a/readme.txt b/readme.txt
index ce52352fc..d3766d795 100644
--- a/readme.txt
+++ b/readme.txt
@@ -77,6 +77,7 @@
 - NEW: Added an initialization function to the lwIP bindings, now it is
        sufficient to call lwipInit(NULL); in order to start the subsystem.
        Demo updated.
+- NIL: Fixed nilrtos redefinition of systime_t (bug #611).
 - HAL: Fixed TIM2 wrongly classified as 32bits in STM32F1xx devices
        (bug #610).