diff --git a/rtc.c b/rtc.c
index 90828d0..e559813 100644
--- a/rtc.c
+++ b/rtc.c
@@ -42,7 +42,7 @@ static int driver_initialised = 0;
 static struct {
   int  (*init)(void);
   void (*fini)(void);
-  void (*time_pre_init)(void);
+  int  (*time_pre_init)(void);
   void (*time_init)(void (*after_hook)(void*), void *anything);
   void (*start_measurements)(void);
   int  (*write_parameters)(void);
diff --git a/rtc_linux.c b/rtc_linux.c
index 66d35e9..613c509 100644
--- a/rtc_linux.c
+++ b/rtc_linux.c
@@ -973,7 +973,7 @@ RTC_Linux_WriteParameters(void)
    etc in this case, since we have fewer requirements regarding the
    RTC behaviour than we do for the rest of the module. */
 
-void
+int
 RTC_Linux_TimePreInit(void)
 {
   int fd, status;
@@ -991,7 +991,7 @@ RTC_Linux_TimePreInit(void)
   fd = open(CNF_GetRtcDevice(), O_RDONLY);
 
   if (fd < 0) {
-    return; /* Can't open it, and won't be able to later */
+    return 0; /* Can't open it, and won't be able to later */
   }
 
   /* Retry reading the rtc until both read attempts give the same sec value.
@@ -1007,6 +1007,8 @@ RTC_Linux_TimePreInit(void)
   /* Read system clock */
   LCL_ReadCookedTime(&old_sys_time, NULL);
 
+  close(fd);
+
   if (status >= 0) {
     /* Convert to seconds since 1970 */
     rtc_tm.tm_sec = rtc_raw.tm_sec;
@@ -1047,10 +1049,11 @@ RTC_Linux_TimePreInit(void)
       }
     } else {
       LOG(LOGS_WARN, LOGF_RtcLinux, "Could not convert RTC reading to seconds since 1/1/1970");
+      return 0;
     }
   }
 
-  close(fd);
+  return 1;
 }
 
 /* ================================================== */
diff --git a/rtc_linux.h b/rtc_linux.h
index 4ac13e1..8cf23a6 100644
--- a/rtc_linux.h
+++ b/rtc_linux.h
@@ -30,7 +30,7 @@
 
 extern int RTC_Linux_Initialise(void);
 extern void RTC_Linux_Finalise(void);
-extern void RTC_Linux_TimePreInit(void);
+extern int RTC_Linux_TimePreInit(void);
 extern void RTC_Linux_TimeInit(void (*after_hook)(void *), void *anything);
 extern void RTC_Linux_StartMeasurements(void);