diff --git a/lib/error.h b/lib/error.h
index af3c1b56..2ec64d0c 100644
--- a/lib/error.h
+++ b/lib/error.h
@@ -64,6 +64,9 @@ extern "C" {
 ******************************************/
 #define PREFIX(name) ZSTD_error_##name
 
+#ifdef ERROR
+#  undef ERROR   /* reported already defined on VS 2015 by Rich Geldreich */
+#endif
 #define ERROR(name) (size_t)-PREFIX(name)
 
 #define ERROR_LIST(ITEM) \