diff --git a/src/rtl_adsb.c b/src/rtl_adsb.c
index 6dbb1bf..33a8775 100644
--- a/src/rtl_adsb.c
+++ b/src/rtl_adsb.c
@@ -45,6 +45,7 @@
 
 #ifdef _WIN32
 #define sleep Sleep
+#define round(x) (x > 0.0 ? floor(x + 0.5): ceil(x - 0.5))
 #endif
 
 #define ADSB_RATE			2000000