diff --git a/usr.bin/vmstat/vmstat.c b/usr.bin/vmstat/vmstat.c
index 640af527bc4c..bc734f045a12 100644
--- a/usr.bin/vmstat/vmstat.c
+++ b/usr.bin/vmstat/vmstat.c
@@ -288,13 +288,13 @@ main(int argc, char *argv[])
 				namelist[X_SUM].n_name = "_cnt";
 				goto retry_nlist;
 			}
-			for (c = 0; c < nitems(namelist); c++)
+			for (c = 0; c < (int)(nitems(namelist)); c++)
 				if (namelist[c].n_type == 0)
 					bufsize += strlen(namelist[c].n_name) + 1;
 			bufsize += len + 1;
 			buf = bp = alloca(bufsize);
 
-			for (c = 0; c < nitems(namelist); c++)
+			for (c = 0; c < (int)(nitems(namelist)); c++)
 				if (namelist[c].n_type == 0) {
 					xo_error(" %s",
 					    namelist[c].n_name);