diff --git a/cpu/fe310/include/periph_cpu.h b/cpu/fe310/include/periph_cpu.h
index dcc468fce1..dd033c813a 100644
--- a/cpu/fe310/include/periph_cpu.h
+++ b/cpu/fe310/include/periph_cpu.h
@@ -173,8 +173,12 @@ typedef struct {
 #define RTT_MIN_FREQUENCY   (1U)                    /* in Hz */
 
 #ifndef RTT_FREQUENCY
+#ifdef MODULE_PERIPH_RTC
+#define RTT_FREQUENCY       (RTT_MIN_FREQUENCY)     /* in Hz */
+#else
 #define RTT_FREQUENCY       (RTT_MAX_FREQUENCY)     /* in Hz */
 #endif
+#endif
 
 
 /** @} */