diff --git a/bitpack.h b/bitpack.h
index 27ea0b6..c43c37a 100644
--- a/bitpack.h
+++ b/bitpack.h
@@ -24,13 +24,16 @@
 //     bitpack.h - "Integer Compression" Binary Packing header file
 #ifndef BITPACK_H_
 #define BITPACK_H_
+#if defined(_MSC_VER) && _MSC_VER < 1600
+#include "vs/stdint.h"
+#else 
+#include <stdint.h>
+#endif
+#include <stddef.h>
 
 #ifdef __cplusplus
 extern "C" {
 #endif
-#include <stdint.h>
-#include <stddef.h>
-
 //******************** Bit Packing High Level API - n unlimited ***************************************************
 size_t bitnpack8(     uint8_t  *__restrict in, size_t n, unsigned char *__restrict out); 
 size_t bitnpack16(    uint16_t *__restrict in, size_t n, unsigned char *__restrict out); 
@@ -135,7 +138,7 @@ unsigned char *bitunpack64( const unsigned char *__restrict in, unsigned n, uint
 
 // ---------------- Direct Access to a single packed integer array entry --------------------------------------------------------------
   #ifndef NTURBOPFOR_DAC
-    #if __AVX2__
+    #if defined(__AVX2__) && defined(AVX2_ON)
 #include <immintrin.h>
 #define bzhi64(_u_, _b_) _bzhi_u64(_u_, _b_)
 #define bzhi32(_u_, _b_) _bzhi_u32(_u_, _b_)