diff --git a/arch/s390/include/asm/timex.h b/arch/s390/include/asm/timex.h
index 670f14a228e5..6bf3a45ccfec 100644
--- a/arch/s390/include/asm/timex.h
+++ b/arch/s390/include/asm/timex.h
@@ -155,7 +155,7 @@ static inline void get_tod_clock_ext(char *clk)
 
 static inline unsigned long long get_tod_clock(void)
 {
-	unsigned char clk[STORE_CLOCK_EXT_SIZE];
+	char clk[STORE_CLOCK_EXT_SIZE];
 
 	get_tod_clock_ext(clk);
 	return *((unsigned long long *)&clk[1]);