diff --git a/src/shared/watchdog.c b/src/shared/watchdog.c
index b42d241528..53c7189e24 100644
--- a/src/shared/watchdog.c
+++ b/src/shared/watchdog.c
@@ -88,7 +88,7 @@ static int open_watchdog(void) {
         return update_timeout();
 }
 
-int watchdog_set_device(char *path) {
+int watchdog_set_device(const char *path) {
         int r;
 
         r = free_and_strdup(&watchdog_device, path);
diff --git a/src/shared/watchdog.h b/src/shared/watchdog.h
index 794176d310..6e99bbdf56 100644
--- a/src/shared/watchdog.h
+++ b/src/shared/watchdog.h
@@ -6,7 +6,7 @@
 #include "time-util.h"
 #include "util.h"
 
-int watchdog_set_device(char *path);
+int watchdog_set_device(const char *path);
 int watchdog_setup(usec_t timeout);
 int watchdog_ping(void);
 void watchdog_close(bool disarm);