diff --git a/teensy3/pins_teensy.c b/teensy3/pins_teensy.c
index e5c724063..bade6847e 100644
--- a/teensy3/pins_teensy.c
+++ b/teensy3/pins_teensy.c
@@ -387,7 +387,7 @@ void rtc_compensate(int adjust)
 }
 
 __attribute__((weak))
-int _gettimeofday(struct timeval *tv, void *ignore)
+int _gettimeofday(struct timeval *tv, struct timezone *ignore)
 {
 	uint32_t sec = RTC_TSR;
 	uint32_t pre = RTC_TPR;
@@ -411,7 +411,7 @@ void rtc_set(unsigned long t) { }
 void rtc_compensate(int adjust) { }
 
 __attribute__((weak))
-int _gettimeofday(struct timeval *tv, void *ignore) { return -1; }
+int _gettimeofday(struct timeval *tv, struct timezone *ignore) { return -1; }
 
 #endif
 
diff --git a/teensy4/rtc.c b/teensy4/rtc.c
index a7a1285c8..1bb81b40d 100644
--- a/teensy4/rtc.c
+++ b/teensy4/rtc.c
@@ -72,7 +72,8 @@ void rtc_compensate(int adjust __attribute__((unused)))
 // https://github.com/arduino-libraries/ArduinoBearSSL/issues/54
 // https://forum.pjrc.com/threads/70966
 __attribute__((weak))
-int _gettimeofday(struct timeval *tv, void *ignore __attribute__((unused)))
+int _gettimeofday(struct timeval *tv,
+                  struct timezone *ignore __attribute__((unused)))
 {
 	uint32_t hi1 = SNVS_HPRTCMR;
 	uint32_t lo1 = SNVS_HPRTCLR;