diff --git a/include/uv-win.h b/include/uv-win.h
index c6c8394a..a1be7e15 100644
--- a/include/uv-win.h
+++ b/include/uv-win.h
@@ -39,6 +39,20 @@ typedef struct pollfd {
 } WSAPOLLFD, *PWSAPOLLFD, *LPWSAPOLLFD;
 #endif
 
+#ifndef LOCALE_INVARIANT
+# define LOCALE_INVARIANT 0x007f
+#endif
+
+#ifndef _malloca
+# if defined(_DEBUG)
+#  define _malloca(size) malloc(size)
+#  define _freea(ptr) free(ptr)
+# else
+#  define _malloca(size) alloca(size)
+#  define _freea(ptr)
+# endif
+#endif
+
 #include <mswsock.h>
 #include <ws2tcpip.h>
 #include <windows.h>
diff --git a/src/win/process.c b/src/win/process.c
index 166f1a06..4d04a0e9 100644
--- a/src/win/process.c
+++ b/src/win/process.c
@@ -800,10 +800,8 @@ int make_program_env(char* env_block[], WCHAR** dst_ptr) {
       i++;
     } else {
       /* copy var from env_block */
-      DWORD r;
       len = wcslen(*ptr_copy) + 1;
-      r = wmemcpy_s(ptr, (env_len - (ptr - dst)), *ptr_copy, len);
-      assert(!r);
+      wmemcpy(ptr, *ptr_copy, len);
       ptr_copy++;
       if (cmp == 0)
         i++;