diff --git a/include/asm-s390/ptrace.h b/include/asm-s390/ptrace.h
index 332ee73..61f6952 100644
--- a/include/asm-s390/ptrace.h
+++ b/include/asm-s390/ptrace.h
@@ -465,6 +465,14 @@
 #ifdef __KERNEL__
 #define __ARCH_SYS_PTRACE	1
 
+/*
+ * These are defined as per linux/ptrace.h, which see.
+ */
+#define arch_has_single_step()	(1)
+struct task_struct;
+extern void user_enable_single_step(struct task_struct *);
+extern void user_disable_single_step(struct task_struct *);
+
 #define user_mode(regs) (((regs)->psw.mask & PSW_MASK_PSTATE) != 0)
 #define instruction_pointer(regs) ((regs)->psw.addr & PSW_ADDR_INSN)
 #define regs_return_value(regs)((regs)->gprs[2])