diff --git a/include/sysemu/rtc.h b/include/sysemu/rtc.h
index 159702b45b..0fc8ad6fdf 100644
--- a/include/sysemu/rtc.h
+++ b/include/sysemu/rtc.h
@@ -42,7 +42,7 @@
  * The behaviour of the clock whose value this function returns will
  * depend on the -rtc command line option passed by the user.
  */
-void qemu_get_timedate(struct tm *tm, int offset);
+void qemu_get_timedate(struct tm *tm, time_t offset);
 
 /**
  * qemu_timedate_diff: Return difference between a struct tm and the RTC
@@ -53,6 +53,6 @@ void qemu_get_timedate(struct tm *tm, int offset);
  * a timestamp one hour further ahead than the current RTC time
  * then this function will return 3600.
  */
-int qemu_timedate_diff(struct tm *tm);
+time_t qemu_timedate_diff(struct tm *tm);
 
 #endif
diff --git a/softmmu/rtc.c b/softmmu/rtc.c
index 4b2bf75dd6..4904581abe 100644
--- a/softmmu/rtc.c
+++ b/softmmu/rtc.c
@@ -68,7 +68,7 @@ static time_t qemu_ref_timedate(QEMUClockType clock)
     return value;
 }
 
-void qemu_get_timedate(struct tm *tm, int offset)
+void qemu_get_timedate(struct tm *tm, time_t offset)
 {
     time_t ti = qemu_ref_timedate(rtc_clock);
 
@@ -85,7 +85,7 @@ void qemu_get_timedate(struct tm *tm, int offset)
     }
 }
 
-int qemu_timedate_diff(struct tm *tm)
+time_t qemu_timedate_diff(struct tm *tm)
 {
     time_t seconds;