diff --git a/include/mbedtls/lms.h b/include/mbedtls/lms.h
index dba8835..1ba4f3a 100644
--- a/include/mbedtls/lms.h
+++ b/include/mbedtls/lms.h
@@ -44,6 +44,15 @@
 #define MBEDTLS_LMOTS_N_HASH_LEN(type)         (type == MBEDTLS_LMOTS_SHA256_N32_W8 ? 32u : 0)
 #define MBEDTLS_LMOTS_I_KEY_ID_LEN             (16u)
 #define MBEDTLS_LMOTS_Q_LEAF_ID_LEN            (4u)
+#define MBEDTLS_LMOTS_TYPE_LEN                 (4u)
+#define MBEDTLS_LMOTS_P_SIG_DIGIT_COUNT(type)  (type == MBEDTLS_LMOTS_SHA256_N32_W8 ? 34u : 0)
+#define MBEDTLS_LMOTS_C_RANDOM_VALUE_LEN(type) (MBEDTLS_LMOTS_N_HASH_LEN(type))
+
+#define MBEDTLS_LMOTS_SIG_LEN(type) (MBEDTLS_LMOTS_TYPE_LEN + \
+                                     MBEDTLS_LMOTS_C_RANDOM_VALUE_LEN(type) + \
+                                     (MBEDTLS_LMOTS_P_SIG_DIGIT_COUNT(type) * \
+                                      MBEDTLS_LMOTS_N_HASH_LEN(type)))
+
 
 #define MBEDTLS_LMS_TYPE_LEN            (4)
 #define MBEDTLS_LMS_H_TREE_HEIGHT(type) (type == MBEDTLS_LMS_SHA256_M32_H10 ? 10u : 0)