diff --git a/src/os_mswin.c b/src/os_mswin.c
index 4b2f3cf..c7eab50 100644
--- a/src/os_mswin.c
+++ b/src/os_mswin.c
@@ -498,7 +498,7 @@
     }
 }
 
-#if (_MSC_VER >= 1300)
+#if (defined(_MSC_VER) && (_MSC_VER >= 1300)) || defined(__MINGW32__)
 # define OPEN_OH_ARGTYPE intptr_t
 #else
 # define OPEN_OH_ARGTYPE long