diff --git a/kernel/debug/gdbstub.c b/kernel/debug/gdbstub.c
index a11db95..380753e 100644
--- a/kernel/debug/gdbstub.c
+++ b/kernel/debug/gdbstub.c
@@ -946,7 +946,8 @@ int gdb_serial_stub(struct kgdb_state *ks)
 		ptr = remcom_out_buffer;
 		*ptr++ = 'T';
 		ptr = pack_hex_byte(ptr, ks->signo);
-		ptr += strlen(strcpy(ptr, "thread:"));
+		strcpy(ptr, "thread:");
+		ptr += strlen(ptr);
 		int_to_threadref(thref, shadow_pid(current->pid));
 		ptr = pack_threadid(ptr, thref);
 		*ptr++ = ';';