diff --git a/util/osdep.c b/util/osdep.c
index 685c8ae..62072b4 100644
--- a/util/osdep.c
+++ b/util/osdep.c
@@ -207,6 +207,13 @@
     }
 #endif
 
+#ifdef O_DIRECT
+    if (ret == -1 && errno == EINVAL && (flags & O_DIRECT)) {
+        error_report("file system may not support O_DIRECT");
+        errno = EINVAL; /* in case it was clobbered */
+    }
+#endif /* O_DIRECT */
+
     return ret;
 }