diff --git a/arch/s390/boot/mem_detect.c b/arch/s390/boot/mem_detect.c
index 2f949cd9076b..17a32707d17e 100644
--- a/arch/s390/boot/mem_detect.c
+++ b/arch/s390/boot/mem_detect.c
@@ -165,7 +165,7 @@ static void search_mem_end(void)
 
 unsigned long detect_memory(void)
 {
-	unsigned long max_physmem_end;
+	unsigned long max_physmem_end = 0;
 
 	sclp_early_get_memsize(&max_physmem_end);