diff --git a/tests/suites/test_suite_lmots.data b/tests/suites/test_suite_lmots.data
index 0845a17..7ae80e9 100644
--- a/tests/suites/test_suite_lmots.data
+++ b/tests/suites/test_suite_lmots.data
@@ -13,26 +13,75 @@
 # signs the message, and verifies the signature.
 lmots_sign_verify_null_msg_test::"00000000000000000000000000000000":12:"be5fa89144f2d665c66ead8216bc02006e0eccd8b3697a0aea44f6c93afe7955"
 
-LMOTS hash-sigs interop test #1
-# This test uses data from https://github.com/cisco/hash-sigs due to the limited
-# amount of available test vectors for LMOTS. A public/private key was generated
-# and used to sign a randomly generated message. We expect this
-# message/signature/public key trio to verify correctly.
-lmots_verify_test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
+LMOTS hsslms interop test #1
+# This test uses data from https://github.com/pmvr/python-hsslms due to the
+# limited amount of available test vectors for LMOTS, and few implementations
+# providing direct access to the underlying OTS signature scheme. The private
+# key is stored in data_files/lms_hsslms_sha256_m32_h5_lmots_sha256_n32_w8.prv.
+# This test uses the same OTS key as the LMS hsslms interop test 1 (leaf 0 of
+# the LMS key), and the same message.
+#
+# To reproduce the signature:
+# sudo pip3 install hsslms==0.1.2
+#
+# from hsslms import LMS_Priv, LM_OTS_Priv, LMS_ALGORITHM_TYPE, LMOTS_ALGORITHM_TYPE
+# import pickle
+#
+# with open('tests/data_files/lms_lmshss_sha256_m32_h5_lmots_sha256_n32_w8.prv', 'rb') as private_key_file:
+#     private_key = pickle.load(private_key_file)
+#
+# ots_private_key = LM_OTS_Priv(private_key.otstypecode, private_key.I, 0, private_key.SEED)
+# ots_public_key = ots_private_key.gen_pub()
+# message = bytes.fromhex('60da1a17c88c59da8a730e6ca8effd37')
+# sig = ots_private_key.sign(message)
+# print('lmots_verify_test:"{}":"{}":"{}":0'.format(message.hex(), sig.hex(), ots_public_key.pubkey.hex()))
+lmots_verify_test:"60da1a17c88c59da8a730e6ca8effd37":"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":"0000000447cc5b29dd0cecd01c382434a6d1686400000000761e8e577fb4d12058806fc7bdaaef0ba64e454dc59b0230a77b43bbd83dc8c6":0
 
-LMOTS hash-sigs interop test #2
-# This test uses data from https://github.com/cisco/hash-sigs due to the limited
-# amount of available test vectors for LMOTS. A public/private key was generated
-# and used to sign a randomly generated message. We expect this
-# message/signature/public key trio to verify correctly.
-lmots_verify_test:"85A77D026E8C704B14EF665DEB0A648350FA8859":"00000004BEEF900CA9A14982E011A5A94503D566288932AD4B9CB85D1551C766A56F788B0D223FBA0E1AD722BE48365B4CE5DA21051B3A79EAD8C1046944192EE51E162DE1E9AE9B13DD8FA90867A17666CB8967F7CD7F4F5383703CCFF555EEBDC8123AF3C4E39D0A5D61725B6A7F23CE587D256C08D31510BCD895106CD524B432A9211CDCBDF5ADDAD5F1D76D428A76DF2556FFA8AB546CFAAA7F2FE86164B976FDA2940498DB0D1A2DE29972FFD55D83E7CA3318DBAC31670565A1E5F59E36342F887E0EF7855AD93CA5F1951307D79EEA375168BC35A3A0B053AEBDB4D7157AD929B0D7DE9FC1E8C32C9A2D679843CBC77560EEDA5959D0AC8407648344C6952649A303E7B6FCC2EE979E1B2786B898A01E2918894DB4E37A0ED79A30260A45959B4BB3016F081181190CB740376389827B2D56DF7EC00871DC9A198B74C7C6086C940A845D54198F2D5DD7A47F97A192F33A85AAA1304A3251B82AC33C5E7B3BA20D2A9BD49BBEE0B2DA2338E578E6F139BB7596DC3BD89E86CB393C42765B9FE85457116906C3F9A8499CF5E539A5CCB3F6D1F36CA209DE6942F807E579AF0EBF072EA110A812C9E420647CE7C8B2BDBB5F56C5B3B7EA80A53C3574F4ED32E4708DFEED60280ABBE2021B3791B0CB09C1F0731353234A6A327CDDFD4E3E2D9DD5A16FCDE3EEF09C67065BD702C07B53A005D3FE7D23FFD77D40E49C82165EB104343A166E808A3CAEDE1A43AE3A82E1788B49C565CF88A2AB8E2FD37657D53E3679D7A818D864F55144011AB498A4A985C46342F3562FD80ECB86497C3DBB759006E5FFFDC01CAA15C69B716174EDCB6E9870CF391003D3826451D1BEFDCC84C093428EE01DAF883190F5D2542B36A7DE44A453AECD5E93B768ACEE75076BE3D73A66F17CFD8E4A49B1F61CE9446815A86FF5FB0EA070A751893C85360C038A161D3DD4D2C66F440E7265153AB346EF620156605C028DD9636FAE0C9A20DF09303ECC5E57A6424505530F70D25F1C95FE51CBD82C2AD0015EB9AD5379CEC463FA0331A14DD971B7C2311FC45979C531653E7252884BAB7C49F8CD652BDF6FDFA76984445C63B54ED22B4A8A267D091381BE7B9B7608133968BA46106BF42B9091F78C085E674D1F70FB91C68D07733F6412B1583DD2F37C6ECAD6BCCE1A1C7D0A7CA80677F679A5AFE08D15427E5C78CE6EB9AA90F51F40343DC9FD1316DCEB2C1EF8EA217B714B0DE1AEECE04D19D0D7757481EDA6E8C51BE85B7B24720E8D62B8AEC56C1A1B9D278B874AACC0B492CF44ED4E7B1200C82323C1AFA0FC776E92B227E8979E3A92EAB05FCF18A43AE648397088F4991F73ECE22C03B3F42F51C0C0FE0DF37919D048FB473F7AB0E33310B9782DE56384BD888CE5E2A644E20A52DD47F710DB0D3169991E29E716ABFD84CA4850080B6C252CB96CD8979189819E532DF56ECB172F773919733BF4D442901EBFB656EBFED4C6D83FAFF288279779499091C94432ECDF83188048AB596D65BC48FA708D485F9CDC50C8B470DFE22157E8F5EE366722A04E8CE7B861573E5FC97D34055BB50B562738F803B202F7F8":"00000004DE9CE10EA7125AC6399B6B3C7EE24224000000161D61E675F3EA19C5B95DA4EE2E35BA061B39E7639F3989F8AE4B0696B3F87E4E":0
+LMOTS hsslms interop test #2
+# This test uses data from https://github.com/pmvr/python-hsslms due to the
+# limited amount of available test vectors for LMOTS, and few implementations
+# providing direct access to the underlying OTS signature scheme. The private
+# key is stored in data_files/lms_hsslms_sha256_m32_h5_lmots_sha256_n32_w8.prv.
+# This test uses the same OTS key as the LMS hsslms interop test 2 (leaf 1 of
+# the LMS key), and the same message.
+#
+# To reproduce the signature:
+# sudo pip3 install hsslms==0.1.2
+#
+# from hsslms import LMS_Priv, LM_OTS_Priv, LMS_ALGORITHM_TYPE, LMOTS_ALGORITHM_TYPE
+# import pickle
+#
+# with open('tests/data_files/lms_lmshss_sha256_m32_h5_lmots_sha256_n32_w8.prv', 'rb') as private_key_file:
+#     private_key = pickle.load(private_key_file)
+#
+#ots_private_key = LM_OTS_Priv(private_key.otstypecode, private_key.I, 1, private_key.SEED)
+#ots_public_key = ots_private_key.gen_pub()
+#message = bytes.fromhex('92d036bde8c45b8bb5dea2a072560b1e29fc4bb7dc4549ce90bccee8a6e962a1')
+#sig = ots_private_key.sign(message)
+#print('lmots_verify_test:"{}":"{}":"{}":0'.format(message.hex(), sig.hex(), ots_public_key.pubkey.hex()))
+lmots_verify_test:"92d036bde8c45b8bb5dea2a072560b1e29fc4bb7dc4549ce90bccee8a6e962a1":"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":"0000000447cc5b29dd0cecd01c382434a6d1686400000001f337dde97685d008a4440b59550277390018d3f1d485fa4b8c91796032de494b":0
 
-LMOTS hash-sigs interop test #3
-# This test uses data from https://github.com/cisco/hash-sigs due to the limited
-# amount of available test vectors for LMOTS. A public/private key was generated
-# and used to sign a randomly generated message. We expect this
-# message/signature/public key trio to verify correctly.
-lmots_verify_test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
+LMOTS hsslms interop NULL-message test
+# This test uses data from https://github.com/pmvr/python-hsslms due to the
+# limited amount of available test vectors for LMOTS, and few implementations
+# providing direct access to the underlying OTS signature scheme. The private
+# key is stored in data_files/lms_hsslms_sha256_m32_h5_lmots_sha256_n32_w8.prv.
+#
+# To reproduce the signature:
+# sudo pip3 install hsslms==0.1.2
+#
+# from hsslms import LMS_Priv, LM_OTS_Priv, LMS_ALGORITHM_TYPE, LMOTS_ALGORITHM_TYPE
+# import pickle
+#
+# with open('tests/data_files/lms_lmshss_sha256_m32_h5_lmots_sha256_n32_w8.prv', 'rb') as private_key_file:
+#     private_key = pickle.load(private_key_file)
+#
+#ots_private_key = LM_OTS_Priv(private_key.otstypecode, private_key.I, 3, private_key.SEED)
+#ots_public_key = ots_private_key.gen_pub()
+#message = bytes()
+#sig = ots_private_key.sign(message)
+#print('lmots_verify_test:"{}":"{}":"{}":0'.format(message.hex(), sig.hex(), ots_public_key.pubkey.hex()))
+lmots_verify_test:"":"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":"0000000447cc5b29dd0cecd01c382434a6d16864000000033fa1330497e44e2773f08e4727eb4d745db9051d6a60779e58a922dc8a7d4ede":0
 
 LMOTS hash-sigs interop negative test (altered random value)
 # This test uses data from https://github.com/cisco/hash-sigs due to the limited
diff --git a/tests/suites/test_suite_lmots.function b/tests/suites/test_suite_lmots.function
index 4821ce5..27a74b6 100644
--- a/tests/suites/test_suite_lmots.function
+++ b/tests/suites/test_suite_lmots.function
@@ -76,7 +76,7 @@
 
 /* BEGIN_CASE */
 void lmots_verify_test ( data_t *msg, data_t *sig, data_t *pub_key,
-                          int expected_rc )
+                         int expected_rc )
 {
     mbedtls_lmots_public_t ctx;
     unsigned int size;
@@ -91,17 +91,20 @@
     /* Test negative cases if the input data is valid */
     if( expected_rc == 0 )
     {
-        /* Altering first message byte must cause verification failure */
-        msg->x[0] ^= 1;
-        TEST_EQUAL(mbedtls_lmots_verify( &ctx, msg->x, msg->len, sig->x, sig->len ),
-                   MBEDTLS_ERR_LMS_VERIFY_FAILED);
-        msg->x[0] ^= 1;
+        if( msg->len >= 1 )
+        {
+            /* Altering first message byte must cause verification failure */
+            msg->x[0] ^= 1;
+            TEST_EQUAL(mbedtls_lmots_verify( &ctx, msg->x, msg->len, sig->x, sig->len ),
+                       MBEDTLS_ERR_LMS_VERIFY_FAILED);
+            msg->x[0] ^= 1;
 
-        /* Altering last message byte must cause verification failure */
-        msg->x[msg->len - 1] ^= 1;
-        TEST_EQUAL(mbedtls_lmots_verify( &ctx, msg->x, msg->len, sig->x, sig->len ),
-                   MBEDTLS_ERR_LMS_VERIFY_FAILED);
-        msg->x[msg->len - 1] ^= 1;
+            /* Altering last message byte must cause verification failure */
+            msg->x[msg->len - 1] ^= 1;
+            TEST_EQUAL(mbedtls_lmots_verify( &ctx, msg->x, msg->len, sig->x, sig->len ),
+                       MBEDTLS_ERR_LMS_VERIFY_FAILED);
+            msg->x[msg->len - 1] ^= 1;
+        }
 
         /* Altering first signature byte must cause verification failure */
         sig->x[0] ^= 1;