diff --git a/testsuite/serpent-test.m4 b/testsuite/serpent-test.m4
index d46a8f3c546527a972b03e6b7605fb9060b54bad..f51b54057030ae67aaecf7a5148cb1abc0ac0add 100644
--- a/testsuite/serpent-test.m4
+++ b/testsuite/serpent-test.m4
@@ -8,6 +8,100 @@ uint8_t msg[SERPENT_BLOCK_SIZE];
 uint8_t cipher[SERPENT_BLOCK_SIZE];
 uint8_t clear[SERPENT_BLOCK_SIZE];
 
-/* FIXME: No tests! */
+/* The first test for each key size from the ecb_vk.txt and ecb_vt.txt
+ * files in the serpent package. */
+
+/* 128 bit key */
+
+/* vk, 1 */
+H(msg, "0000000000000000 0000000000000000");
+
+serpent_set_key(&ctx, 16, H("8000000000000000 0000000000000000"));
+serpent_encrypt(&ctx, SERPENT_BLOCK_SIZE, cipher, msg);
+
+if (!MEMEQ(SERPENT_BLOCK_SIZE, cipher,
+	H("49AFBFAD9D5A3405 2CD8FFA5986BD2DD")))
+  FAIL;
+
+serpent_decrypt(&ctx, SERPENT_BLOCK_SIZE, clear, cipher);
+if (!MEMEQ(SERPENT_BLOCK_SIZE, msg, clear))
+  FAIL;
+
+/* vt, 1 */
+H(msg, "8000000000000000 0000000000000000");
+
+serpent_set_key(&ctx, 16, H("0000000000000000 0000000000000000"));
+serpent_encrypt(&ctx, SERPENT_BLOCK_SIZE, cipher, msg);
+
+if (!MEMEQ(SERPENT_BLOCK_SIZE, cipher,
+	H("10B5FFB720B8CB90 02A1142B0BA2E94A")))
+  FAIL;
+
+serpent_decrypt(&ctx, SERPENT_BLOCK_SIZE, clear, cipher);
+if (!MEMEQ(SERPENT_BLOCK_SIZE, msg, clear))
+  FAIL;
+
+/* 192 bit key */
+
+/* vk, 1 */
+H(msg, "0000000000000000 0000000000000000");
+
+serpent_set_key(&ctx, 24, H("8000000000000000 0000000000000000"
+			    "0000000000000000"));
+serpent_encrypt(&ctx, SERPENT_BLOCK_SIZE, cipher, msg);
+
+if (!MEMEQ(SERPENT_BLOCK_SIZE, cipher,
+	H("E78E5402C7195568 AC3678F7A3F60C66")))
+  FAIL;
+
+serpent_decrypt(&ctx, SERPENT_BLOCK_SIZE, clear, cipher);
+if (!MEMEQ(SERPENT_BLOCK_SIZE, msg, clear))
+  FAIL;
+
+/* vt, 1 */
+H(msg, "8000000000000000 0000000000000000");
+
+serpent_set_key(&ctx, 24, H("0000000000000000 0000000000000000"
+			    "0000000000000000"));
+serpent_encrypt(&ctx, SERPENT_BLOCK_SIZE, cipher, msg);
+
+if (!MEMEQ(SERPENT_BLOCK_SIZE, cipher,
+	H("B10B271BA25257E1 294F2B51F076D0D9")))
+  FAIL;
+
+serpent_decrypt(&ctx, SERPENT_BLOCK_SIZE, clear, cipher);
+if (!MEMEQ(SERPENT_BLOCK_SIZE, msg, clear))
+  FAIL;
+
+/* 256 bit key */
+
+/* vk, 1 */
+H(msg, "0000000000000000 0000000000000000");
+
+serpent_set_key(&ctx, 32, H("8000000000000000 0000000000000000"
+			    "0000000000000000 0000000000000000"));
+serpent_encrypt(&ctx, SERPENT_BLOCK_SIZE, cipher, msg);
+
+if (!MEMEQ(SERPENT_BLOCK_SIZE, cipher,
+	H("ABED96E766BF28CB C0EBD21A82EF0819")))
+  FAIL;
+
+serpent_decrypt(&ctx, SERPENT_BLOCK_SIZE, clear, cipher);
+if (!MEMEQ(SERPENT_BLOCK_SIZE, msg, clear))
+  FAIL;
+
+/* vt, 1 */
+H(msg, "8000000000000000 0000000000000000");
+
+serpent_set_key(&ctx, 32, H("0000000000000000 0000000000000000"
+			    "0000000000000000 0000000000000000"));
+serpent_encrypt(&ctx, SERPENT_BLOCK_SIZE, cipher, msg);
+
+if (!MEMEQ(SERPENT_BLOCK_SIZE, cipher,
+	H("DA5A7992B1B4AE6F 8C004BC8A7DE5520")))
+  FAIL;
+
+serpent_decrypt(&ctx, SERPENT_BLOCK_SIZE, clear, cipher);
+if (!MEMEQ(SERPENT_BLOCK_SIZE, msg, clear))
+  FAIL;
 
-#warning no tests