diff --git a/arch/v850/kernel/ptrace.c b/arch/v850/kernel/ptrace.c
index 8fa7807..4726b87 100644
--- a/arch/v850/kernel/ptrace.c
+++ b/arch/v850/kernel/ptrace.c
@@ -23,6 +23,7 @@
 #include <linux/sched.h>
 #include <linux/smp_lock.h>
 #include <linux/ptrace.h>
+#include <linux/signal.h>
 
 #include <asm/errno.h>
 #include <asm/ptrace.h>
@@ -208,7 +209,7 @@
 	/* Execute a single instruction. */
 	case PTRACE_SINGLESTEP:
 		rval = -EIO;
-		if ((unsigned long) data > _NSIG)
+		if (!valid_signal(data))
 			break;
 
 		/* Turn CHILD's single-step flag on or off.  */