diff --git a/arch/arm/lib/bootm.c b/arch/arm/lib/bootm.c
index ee56d74..a477cae 100644
--- a/arch/arm/lib/bootm.c
+++ b/arch/arm/lib/bootm.c
@@ -290,7 +290,10 @@
 
 	s = getenv("machid");
 	if (s) {
-		strict_strtoul(s, 16, &machid);
+		if (strict_strtoul(s, 16, &machid) < 0) {
+			debug("strict_strtoul failed!\n");
+			return;
+		}
 		printf("Using machid 0x%lx from environment\n", machid);
 	}