diff --git a/include/sysemu/os-posix.h b/include/sysemu/os-posix.h
index 2edf33658a..dd64fb401d 100644
--- a/include/sysemu/os-posix.h
+++ b/include/sysemu/os-posix.h
@@ -55,6 +55,7 @@ int os_mlock(void);
 typedef struct timeval qemu_timeval;
 #define qemu_gettimeofday(tp) gettimeofday(tp, NULL)
 
+int os_set_daemonize(bool d);
 bool is_daemonized(void);
 
 /**
diff --git a/include/sysemu/os-win32.h b/include/sysemu/os-win32.h
index 43f569b5c2..770752222a 100644
--- a/include/sysemu/os-win32.h
+++ b/include/sysemu/os-win32.h
@@ -77,6 +77,14 @@ typedef struct {
 } qemu_timeval;
 int qemu_gettimeofday(qemu_timeval *tp);
 
+static inline int os_set_daemonize(bool d)
+{
+    if (d) {
+        return -ENOTSUP;
+    }
+    return 0;
+}
+
 static inline bool is_daemonized(void)
 {
     return false;
diff --git a/os-posix.c b/os-posix.c
index ae6c9f2a5e..24692c8593 100644
--- a/os-posix.c
+++ b/os-posix.c
@@ -317,6 +317,12 @@ bool is_daemonized(void)
     return daemonize;
 }
 
+int os_set_daemonize(bool d)
+{
+    daemonize = d;
+    return 0;
+}
+
 int os_mlock(void)
 {
 #ifdef HAVE_MLOCKALL