diff --git a/capability.go b/capability.go
index ed84adc3a..7b291f38c 100644
--- a/capability.go
+++ b/capability.go
@@ -16,7 +16,7 @@ type listCapabilities struct {
 	data []Capability
 }
 
-func NewCapabilites() Capabilities {
+func NewCapabilities() Capabilities {
 	return &listCapabilities{
 		data: make([]Capability, 0, 16),
 	}
diff --git a/capability_test.go b/capability_test.go
new file mode 100644
index 000000000..100daeb72
--- /dev/null
+++ b/capability_test.go
@@ -0,0 +1,21 @@
+package core
+
+import (
+	"testing"
+
+	"github.com/v2ray/v2ray-core/testing/unit"
+)
+
+func TestCapabilities(t *testing.T) {
+	assert := unit.Assert(t)
+
+	caps := NewCapabilities()
+	assert.Bool(caps.HasCapability(TCPConnection)).IsFalse()
+
+	caps.AddCapability(TCPConnection)
+	assert.Bool(caps.HasCapability(TCPConnection)).IsTrue()
+
+	caps.AddCapability(UDPConnection)
+	assert.Bool(caps.HasCapability(TCPConnection)).IsTrue()
+	assert.Bool(caps.HasCapability(UDPConnection)).IsTrue()
+}