diff --git a/src/option.c b/src/option.c
index c18672e..f691f50 100644
--- a/src/option.c
+++ b/src/option.c
@@ -3181,7 +3181,7 @@
 	    if (opt_idx >= 0)
 	    {
 #if !defined(HAVE_AVAIL_MEM) && !defined(HAVE_TOTAL_MEM)
-		if ((long)options[opt_idx].def_val[VI_DEFAULT] > n
+		if ((long)options[opt_idx].def_val[VI_DEFAULT] > (long)n
 			|| (long)options[opt_idx].def_val[VI_DEFAULT] == 0L)
 #endif
 		    options[opt_idx].def_val[VI_DEFAULT] = (char_u *)n;