diff --git a/osdep.h b/osdep.h
index 27eedcf..5e48860 100644
--- a/osdep.h
+++ b/osdep.h
@@ -8,9 +8,7 @@
 #include <sys/signal.h>
 #endif
 
-#ifndef _WIN32
 #include <sys/time.h>
-#endif
 
 #ifndef glue
 #define xglue(x, y) x ## y
@@ -131,4 +129,21 @@
 
 int qemu_create_pidfile(const char *filename);
 
+#ifdef _WIN32
+static inline void qemu_timersub(const struct timeval *val1,
+                                 const struct timeval *val2,
+                                 struct timeval *res)
+{
+    res->tv_sec = val1->tv_sec - val2->tv_sec;
+    if (val1->tv_usec < val2->tv_usec) {
+        res->tv_sec--;
+        res->tv_usec = val1->tv_usec - val2->tv_usec + 1000 * 1000;
+    } else {
+        res->tv_usec = val1->tv_usec - val2->tv_usec;
+    }
+}
+#else
+#define qemu_timersub timersub
+#endif
+
 #endif