diff --git a/ac.h b/ac.h
index b547b88..3b09ac3 100644
--- a/ac.h
+++ b/ac.h
@@ -4,7 +4,11 @@
 extern "C" {
 #endif
 
+#ifndef _MSC_VER
 #define AC_EXPORT __attribute__ ((visibility ("default")))
+#else
+#define AC_EXPORT
+#endif
 
 /* If the subject-string doesn't match any of the given patterns, "match_begin"
  * should be a negative; otherwise the substring of the subject-string,
diff --git a/ac_fast.cxx b/ac_fast.cxx
index 1cf145f..90991c1 100644
--- a/ac_fast.cxx
+++ b/ac_fast.cxx
@@ -11,7 +11,7 @@ AC_Converter::Calc_State_Sz(const ACS_State* s) const {
     if (sz < sizeof(AC_State))
         sz = sizeof(AC_State);
 
-    uint32 align = __alignof__(dummy);
+    uint32 align = __alignof(dummy);
     sz = (sz + align - 1) & ~(align - 1);
     return sz;
 }
@@ -35,14 +35,14 @@ AC_Converter::Alloc_Buffer() {
         root_goto_ofst = 0;
 
     // part 3: mapping of state's relative position.
-    unsigned align = __alignof__(AC_Ofst);
+    unsigned align = __alignof(AC_Ofst);
     sz = (sz + align - 1) & ~(align - 1);
     states_ofst_ofst = sz;
 
     sz += sizeof(AC_Ofst) * all_states.size();
 
     // part 4: state's contents
-    align = __alignof__(AC_State);
+    align = __alignof(AC_State);
     sz = (sz + align - 1) & ~(align - 1);
     first_state_ofst = sz;
 
@@ -82,7 +82,7 @@ AC_Converter::Populate_Root_Goto_Func(AC_Buffer* buf,
     uint32 new_id = 1;
     bool full_fantout = (goto_vect.size() == 255);
     if (likely(!full_fantout))
-        bzero(root_gotos, 256*sizeof(InputTy));
+        memset(root_gotos, 0, 256 * sizeof(InputTy));
 
     for (GotoVect::iterator i = goto_vect.begin(), e = goto_vect.end();
             i != e; i++, new_id++) {
@@ -212,7 +212,14 @@ Get_State_Addr(unsigned char* buf_base, AC_Ofst* StateOfstVect, uint32 state_id)
 // 10+ benchmarks. It's still too early to say which one works better.
 //
 #if !defined(BS_MULTI_VER)
-static bool __attribute__((always_inline)) inline
+
+#ifdef _MSC_VER
+#define INLINE_FLAG inline __forceinline
+#else
+#define INLINE_FLAG inline __attribute__((always_inline))
+#endif
+
+static bool INLINE_FLAG
 Binary_Search_Input(InputTy* input_vect, int vect_len, InputTy input, int& idx) {
     if (vect_len <= 8) {
         for (int i = 0; i < vect_len; i++) {
diff --git a/ac_slow.cxx b/ac_slow.cxx
index cb3957a..ac06bbb 100644
--- a/ac_slow.cxx
+++ b/ac_slow.cxx
@@ -1,5 +1,4 @@
 #include <ctype.h>
-#include <strings.h> // for bzero
 #include <algorithm>
 #include "ac_slow.hpp"
 #include "ac.h"
@@ -13,7 +12,7 @@
 ACS_Constructor::ACS_Constructor() : _next_node_id(1) {
     _root = new_state();
     _root_char = new InputTy[256];
-    bzero((void*)_root_char, 256);
+    memset((void*)_root_char, 0, 256 * sizeof(InputTy));
 
 #ifdef VERIFY
     _pattern_buf = 0;
diff --git a/ac_util.hpp b/ac_util.hpp
index 0815193..e0d89ea 100644
--- a/ac_util.hpp
+++ b/ac_util.hpp
@@ -48,8 +48,13 @@ typedef unsigned char InputTy;
     #define ASSERT(c) ((void)0)
 #endif
 
+#ifndef _MSC_VER
 #define likely(x)   __builtin_expect((x),1)
 #define unlikely(x) __builtin_expect((x),0)
+#else
+#define likely(x)   (x)
+#define unlikely(x) (x)
+#endif
 
 #ifndef offsetof
 #define offsetof(st, m) ((size_t)(&((st *)0)->m))