diff --git a/cmd/elf.c b/cmd/elf.c
index 6b49c61..5e0ee30 100644
--- a/cmd/elf.c
+++ b/cmd/elf.c
@@ -247,7 +247,7 @@
 			ptr += sprintf(build_buf + ptr, "e=%s", tmp);
 			tmp = env_get("netmask");
 			if (tmp) {
-				u32 mask = env_get_ip("netmask").s_addr;
+				u32 mask = string_to_ip(tmp).s_addr;
 				ptr += sprintf(build_buf + ptr,
 					       ":%08x ", ntohl(mask));
 			} else {