diff --git a/arch/s390/kernel/compat_ptrace.h b/arch/s390/kernel/compat_ptrace.h
index a2be3a9..123dd66 100644
--- a/arch/s390/kernel/compat_ptrace.h
+++ b/arch/s390/kernel/compat_ptrace.h
@@ -1,10 +1,11 @@
 #ifndef _PTRACE32_H
 #define _PTRACE32_H
 
+#include <asm/ptrace.h>    /* needed for NUM_CR_WORDS */
 #include "compat_linux.h"  /* needed for psw_compat_t */
 
 typedef struct {
-	__u32 cr[3];
+	__u32 cr[NUM_CR_WORDS];
 } per_cr_words32;
 
 typedef struct {