diff --git a/Makefile b/Makefile
index bc8c57c..68a0cf0 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,7 @@
 LIBRARY=bessel
 
 $(LIBRARY).js: bessel.md
+	@[ -e node_modules/voc ] && true || npm install voc
 	node_modules/.bin/voc $^ > $@
 
 test mocha:
diff --git a/package.json b/package.json
index ec15861..f6bf012 100644
--- a/package.json
+++ b/package.json
@@ -11,7 +11,6 @@
 		"test": "make test"
 	},
 	"dependencies": {
-		"voc":""
 	},
 	"devDependencies": {
 		"mocha":""
diff --git a/test.js b/test.js
index bb45acb..000c61c 100644
--- a/test.js
+++ b/test.js
@@ -17,6 +17,6 @@ describe('When using bessel functions', function() {
     assert(Math.floor((bessel.besselk(1.5, 1) - 0.277388) * 10e6) < 10);
   });
   it('It must compute Weber\'s Bessel function at 2.5 with an order of 1 (0.145918)', function() {
-    assert(Math.floor((bessel.besselk(2.5, 1) - 0.981666) * 10e6) < 10);
+    assert(Math.floor((bessel.bessely(2.5, 1) - 0.145918) * 10e6) < 10);
   });
 });