diff --git a/util.c b/util.c
index 88765ca..18d29b7 100644
--- a/util.c
+++ b/util.c
@@ -1169,6 +1169,116 @@
 # define CLONE_STOPPED   0x02000000
 #endif
 
+static int
+change_syscall(struct tcb *tcp, int new)
+{
+#if defined(I386)
+	if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(ORIG_EAX * 4), new) < 0)
+		return -1;
+	return 0;
+#elif defined(X86_64)
+	if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(ORIG_RAX * 8), new) < 0)
+		return -1;
+	return 0;
+#elif defined(POWERPC)
+	if (ptrace(PTRACE_POKEUSER, tcp->pid,
+		   (char*)(sizeof(unsigned long)*PT_R0), new) < 0)
+		return -1;
+	return 0;
+#elif defined(S390) || defined(S390X)
+	/* s390 linux after 2.4.7 has a hook in entry.S to allow this */
+	if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(PT_GPR2), new) < 0)
+		return -1;
+	return 0;
+#elif defined(M68K)
+	if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(4*PT_ORIG_D0), new) < 0)
+		return -1;
+	return 0;
+#elif defined(SPARC) || defined(SPARC64)
+	struct pt_regs regs;
+	if (ptrace(PTRACE_GETREGS, tcp->pid, (char*)&regs, 0) < 0)
+		return -1;
+	regs.u_regs[U_REG_G1] = new;
+	if (ptrace(PTRACE_SETREGS, tcp->pid, (char*)&regs, 0) < 0)
+		return -1;
+	return 0;
+#elif defined(MIPS)
+	if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(REG_V0), new) < 0)
+		return -1;
+	return 0;
+#elif defined(ALPHA)
+	if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(REG_A3), new) < 0)
+		return -1;
+	return 0;
+#elif defined(AVR32)
+	if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(REG_R8), new) < 0)
+		return -1;
+	return 0;
+#elif defined(BFIN)
+	if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(REG_P0), new) < 0)
+		return -1;
+	return 0;
+#elif defined(IA64)
+	if (ia32) {
+		switch (new) {
+		case 2:
+			break;	/* x86 SYS_fork */
+		case SYS_clone:
+			new = 120;
+			break;
+		default:
+			fprintf(stderr, "%s: unexpected syscall %d\n",
+				__FUNCTION__, new);
+			return -1;
+		}
+		if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(PT_R1), new) < 0)
+			return -1;
+	} else if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(PT_R15), new) < 0)
+		return -1;
+	return 0;
+#elif defined(HPPA)
+	if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(PT_GR20), new) < 0)
+		return -1;
+	return 0;
+#elif defined(SH)
+	if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(4*(REG_REG0+3)), new) < 0)
+		return -1;
+	return 0;
+#elif defined(SH64)
+	/* Top half of reg encodes the no. of args n as 0x1n.
+	   Assume 0 args as kernel never actually checks... */
+	if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(REG_SYSCALL),
+				0x100000 | new) < 0)
+		return -1;
+	return 0;
+#elif defined(CRISV10) || defined(CRISV32)
+	if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(4*PT_R9), new) < 0)
+		return -1;
+	return 0;
+#elif defined(ARM)
+	/* Some kernels support this, some (pre-2.6.16 or so) don't.  */
+# ifndef PTRACE_SET_SYSCALL
+#  define PTRACE_SET_SYSCALL 23
+# endif
+	if (ptrace(PTRACE_SET_SYSCALL, tcp->pid, 0, new & 0xffff) != 0)
+		return -1;
+	return 0;
+#elif defined(TILE)
+	if (ptrace(PTRACE_POKEUSER, tcp->pid,
+		   (char*)PTREGS_OFFSET_REG(0),
+		   new) != 0)
+		return -1;
+	return 0;
+#elif defined(MICROBLAZE)
+	if (ptrace(PTRACE_POKEUSER, tcp->pid, (char*)(PT_GPR(0)), new) < 0)
+		return -1;
+	return 0;
+#else
+#warning Do not know how to handle change_syscall for this architecture
+#endif /* architecture */
+	return -1;
+}
+
 #ifdef IA64
 
 typedef unsigned long *arg_setup_state;