thodg/libgit2

diff --git a/src/win32/posix.h b/src/win32/posix.h
index 2cbea18..22ea6a5 100644
--- a/src/win32/posix.h
+++ b/src/win32/posix.h
@@ -19,7 +19,7 @@
 # define EAFNOSUPPORT (INT_MAX-1)
 #endif
 
-#ifdef _MSC_VER
+#if defined(_MSC_VER) && _MSC_VER >= 1500
 # define p_ftruncate(fd, sz) _chsize_s(fd, sz)
 #else  /* MinGW */
 # define p_ftruncate(fd, sz) _chsize(fd, sz)
diff --git a/src/win32/posix_w32.c b/src/win32/posix_w32.c
index fbadb1c..fb82465 100644
--- a/src/win32/posix_w32.c
+++ b/src/win32/posix_w32.c
@@ -543,7 +543,7 @@ char *p_realpath(const char *orig_path, char *buffer)
 
 int p_vsnprintf(char *buffer, size_t count, const char *format, va_list argptr)
 {
-#ifdef _MSC_VER
+#if defined(_MSC_VER) && _MSC_VER >= 1500
 	int len;
 
 	if (count == 0 ||
@@ -570,7 +570,7 @@ int p_snprintf(char *buffer, size_t count, const char *format, ...)
 
 int p_mkstemp(char *tmp_path)
 {
-#if defined(_MSC_VER)
+#if defined(_MSC_VER) && _MSC_VER >= 1500
 	if (_mktemp_s(tmp_path, strlen(tmp_path) + 1) != 0)
 		return -1;
 #else