diff --git a/board/gdsys/405ep/iocon.c b/board/gdsys/405ep/iocon.c
index 20770e4..ce53340 100644
--- a/board/gdsys/405ep/iocon.c
+++ b/board/gdsys/405ep/iocon.c
@@ -69,8 +69,9 @@
  */
 int checkboard(void)
 {
+	char buf[64];
+	int i = getenv_f("serial#", buf, sizeof(buf));
 	ihs_fpga_t *fpga = (ihs_fpga_t *) CONFIG_SYS_FPGA_BASE(0);
-	char *s = getenv("serial#");
 	u16 versions = in_le16(&fpga->versions);
 	u16 fpga_version = in_le16(&fpga->fpga_version);
 	u16 fpga_features = in_le16(&fpga->fpga_features);
@@ -98,9 +99,9 @@
 
 	printf("IoCon");
 
-	if (s != NULL) {
+	if (i > 0) {
 		puts(", serial# ");
-		puts(s);
+		puts(buf);
 	}
 	puts("\n       ");