diff --git a/test/c/05-sign-keypair.js b/test/c/05-sign-keypair.js
new file mode 100644
index 00000000..e71685c5
--- /dev/null
+++ b/test/c/05-sign-keypair.js
@@ -0,0 +1,52 @@
+var nacl = require('../../' + (process.env.NACL_SRC || 'nacl.min.js'));
+var crypto = require('crypto');
+var spawn = require('child_process').spawn;
+var execFile = require('child_process').execFile;
+var path = require('path');
+var test = require('tape');
+
+function csign(sk, msg, callback) {
+  var hexsk = (new Buffer(sk)).toString('hex');
+  var p = spawn(path.resolve(__dirname, 'csign'), [hexsk]);
+  var result = [];
+  p.stdout.on('data', function(data) {
+    result.push(data);
+  });
+  p.on('close', function(code) {
+    callback(Buffer.concat(result).toString('base64'));
+  });
+  p.on('error', function(err) {
+    throw err;
+  });
+  p.stdin.write(msg);
+  p.stdin.end();
+}
+
+function csignkeypair(callback) {
+  execFile(path.resolve(__dirname, 'csign-keypair'), [], function(err, stdout) {
+    if (err) throw err;
+    callback(stdout.toString('utf8'));
+  });
+}
+
+test('nacl.sign (C) with keypair from C', function(t) {
+  function check(num) {
+    csignkeypair(function(hexSecretKey) {
+      var secretKey = new Uint8Array(nacl.sign.secretKeyLength);
+      var b = new Buffer(hexSecretKey, 'hex');
+      for (var i = 0; i < b.length; i++) secretKey[i] = b[i];
+      var msg = nacl.randomBytes(num);
+      var signedMsg = nacl.util.encodeBase64(nacl.sign(msg, secretKey));
+      csign(secretKey, new Buffer(msg), function(signedFromC) {
+        t.equal(signedMsg, signedFromC, 'signed messages should be equal');
+        if (num >= 100) {
+          t.end();
+          return;
+        }
+        check(num+1);
+      });
+    });
+  }
+
+  check(0);
+});
diff --git a/test/c/Makefile b/test/c/Makefile
index 80a79d74..933f7c48 100644
--- a/test/c/Makefile
+++ b/test/c/Makefile
@@ -1,6 +1,6 @@
 CFLAGS=-O3
 
-all: csecretbox cscalarmult cbox chash csign
+all: csecretbox cscalarmult cbox chash csign csign-keypair
 
 csecretbox: csecretbox.o tweetnacl.o
 
@@ -12,24 +12,27 @@ chash: chash.o tweetnacl.o
 
 csign: csign.o tweetnacl.o
 
-test: test_secretbox
+csign-keypair: csign-keypair.o tweetnacl.o
 
-#test_scalarmult test_box test_hash test_sign clean
+test: test_secretbox test_scalarmult test_box test_hash test_sign test_signkeypair clean
 
 test_secretbox: csecretbox
-	tap --timeout 1800 ./secretbox.js
+	node ./00-secretbox.js
 
 test_scalarmult: cscalarmult
-	node ./scalarmult.js
+	node ./01-scalarmult.js
 
 test_box: cbox
-	node ./box.js
+	node ./02-box.js
 
 test_hash: chash
-	node ./hash.js
+	node ./03-hash.js
 
 test_sign: csign
-	node ./sign.js
+	node ./04-sign.js
+
+test_signkeypair: csign csign-keypair
+	node ./05-sign-keypair.js
 
 clean:
-	rm *.o csecretbox cscalarmult cbox chash csign
+	rm *.o csecretbox cscalarmult cbox chash csign csign-keypair
diff --git a/test/c/chash.c b/test/c/chash.c
index 9dc04608..4849f8bb 100644
--- a/test/c/chash.c
+++ b/test/c/chash.c
@@ -1,5 +1,5 @@
 /*
- * This program sings a message using tweenacl.c.
+ * This program sings a message using tweetnacl.c.
  * Written by @dchest. Public domain.
  */
 #include <err.h>
diff --git a/test/c/csign-keypair.c b/test/c/csign-keypair.c
new file mode 100644
index 00000000..5d372b02
--- /dev/null
+++ b/test/c/csign-keypair.c
@@ -0,0 +1,53 @@
+/*
+ * This program generates a sign secret key using tweetnacl.c.
+ * Written by @dchest. Public domain.
+ */
+#include <err.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "tweetnacl.h"
+
+void randombytes(unsigned char *x,unsigned long long xlen) {
+	static int fd = -1;
+	int i;
+
+	if (fd == -1) {
+		for (;;) {
+			fd = open("/dev/urandom",O_RDONLY);
+			if (fd != -1) break;
+			sleep(1);
+		}
+	}
+
+	while (xlen > 0) {
+		if (xlen < 1048576) i = xlen; else i = 1048576;
+
+		i = read(fd,x,i);
+		if (i < 1) {
+			sleep(1);
+			continue;
+		}
+
+		x += i;
+		xlen -= i;
+	}
+}
+
+int
+main(int argc, const char **argv)
+{
+	unsigned char pk[crypto_sign_PUBLICKEYBYTES],
+		      sk[crypto_sign_SECRETKEYBYTES];
+	int i;
+
+	crypto_sign_keypair(pk, sk);
+	for (i = 0; i < sizeof(sk); i++)
+		printf("%02x", sk[i]);
+	return 0;
+}
diff --git a/test/c/csign.c b/test/c/csign.c
index ea5214a2..737c5cae 100644
--- a/test/c/csign.c
+++ b/test/c/csign.c
@@ -1,5 +1,5 @@
 /*
- * This program sings a message using tweenacl.c.
+ * This program signs a message using tweetnacl.c.
  * Written by @dchest. Public domain.
  */
 #include <err.h>