diff --git a/kernel/printk/printk_ringbuffer.c b/kernel/printk/printk_ringbuffer.c
index a949d02fbd174..2b2a85222d19d 100644
--- a/kernel/printk/printk_ringbuffer.c
+++ b/kernel/printk/printk_ringbuffer.c
@@ -1477,7 +1477,7 @@ static inline u64 __ulseq_to_u64seq(u32 ulseq)
 	 * sequence. It needs to be expanded to 64bit. Get the first sequence
 	 * number from the ringbuffer and fold it.
 	 */
-	seq = rb_first_seq - ((u32)rb_first_seq - ulseq);
+	seq = rb_first_seq - ((s32)((u32)rb_first_seq - ulseq));
 
 	return seq;
 }
diff --git a/localversion-rt b/localversion-rt
index 08b3e75841adc..18777ec0c27d4 100644
--- a/localversion-rt
+++ b/localversion-rt
@@ -1 +1 @@
--rt14
+-rt15
