diff --git a/lib/hsts.c b/lib/hsts.c
index 0e7c19cfbd..fd4926f36b 100644
--- a/lib/hsts.c
+++ b/lib/hsts.c
@@ -46,8 +46,6 @@
 #define MAX_HSTS_LINE 4095
 #define MAX_HSTS_HOSTLEN 256
 #define MAX_HSTS_HOSTLENSTR "256"
-#define MAX_HSTS_SUBLEN 4
-#define MAX_HSTS_SUBLENSTR "4"
 #define MAX_HSTS_DATELEN 64
 #define MAX_HSTS_DATELENSTR "64"