diff --git a/cJSON.c b/cJSON.c
index 4c6a308..6bc102b 100644
--- a/cJSON.c
+++ b/cJSON.c
@@ -78,8 +78,12 @@
 #endif
 
 #ifndef NAN
+#ifdef _WIN32
+#define NAN sqrt(-1.0)
+#else
 #define NAN 0.0/0.0
 #endif
+#endif
 
 typedef struct {
     const unsigned char *json;