diff --git a/sys/alpha/include/ptrace.h b/sys/alpha/include/ptrace.h
index 1fa28f760fca..5a9cf1492124 100644
--- a/sys/alpha/include/ptrace.h
+++ b/sys/alpha/include/ptrace.h
@@ -47,6 +47,8 @@
 
 #define FIX_SSTEP(p)	ptrace_clear_single_step(p)
 
+#ifdef _KERNEL
 int	ptrace_clear_single_step(struct proc *_p);
+#endif
 
 #endif