diff --git a/main.cpp b/main.cpp
index a82ace48d..f86be6ac3 100644
--- a/main.cpp
+++ b/main.cpp
@@ -24,6 +24,8 @@
 #include <unistd.h>
 #include <sys/mman.h>
 #include <sys/stat.h>
+#elif defined (_POSIX_MAPPED_FILES)
+#include <sys/mman.h>
 #endif
 
 #define ROUNDUP(X, K) (((X) + (K)-1) & -(K))
diff --git a/mmap.h b/mmap.h
index 8bdd662d3..7850fee32 100644
--- a/mmap.h
+++ b/mmap.h
@@ -8,11 +8,12 @@
 #include <stdint.h>
 #include <fcntl.h>
 
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-#ifdef _MSC_VER
+#if defined (_MSC_VER) && !(defined (_POSIX_MAPPED_FILES))
 #define NEED_WIN32_MMAP
 #include <Windows.h>
 #include <io.h>