diff --git a/src/internal.h b/src/internal.h
index 4a63984cecd484a095850a55d16dfcdf5dd4cc81..8c9322ec1e2e84a9971afb984a5b5cf0ab241cf5 100644
--- a/src/internal.h
+++ b/src/internal.h
@@ -89,6 +89,12 @@
 
 #define NUL_TERMINATE(buf) do { (buf)[sizeof(buf)-1] = '\0'; } while (0)
 
+#ifdef WIN32
+# ifndef O_CLOEXEC
+#  define O_CLOEXEC _O_NOINHERIT
+# endif
+#endif
+
 /**
  * G_GNUC_NO_INLINE:
  *