--- a/Utilities/gdcmext/mec_mr3_io.c
+++ b/Utilities/gdcmext/mec_mr3_io.c
@@ -132,7 +67,7 @@
 }
 
 static void *aligned_alloc_impl(size_t alignment, size_t size) {
-#ifdef _MSC_VER
+#ifdef _WIN32
   return _aligned_malloc(size, alignment);
 #else
   // return aligned_alloc(alignment, size);
@@ -835,7 +835,7 @@
     good = good && read_group(self, group, nitems, &info, &data);
   }
   // release memory:
-#ifdef _MSC_VER
+#ifdef _WIN32
   _aligned_free(data.buffer);
 #else
   free(data.buffer);
