diff --git a/lib/seq_buf.c b/lib/seq_buf.c
index bd807f545a9d..b15dbb6f061a 100644
--- a/lib/seq_buf.c
+++ b/lib/seq_buf.c
@@ -242,12 +242,14 @@ int seq_buf_putmem_hex(struct seq_buf *s, const void *mem,
 			break;
 
 		/* j increments twice per loop */
-		len -= j / 2;
 		hex[j++] = ' ';
 
 		seq_buf_putmem(s, hex, j);
 		if (seq_buf_has_overflowed(s))
 			return -1;
+
+		len -= start_len;
+		data += start_len;
 	}
 	return 0;
 }