diff --git a/Source/Constraint.swift b/Source/Constraint.swift
index 60e0f2f..4f291e6 100644
--- a/Source/Constraint.swift
+++ b/Source/Constraint.swift
@@ -193,18 +193,18 @@ internal class ConcreteConstraint: Constraint {
         }
     }
     
-    private let identifier: String?
+    private let label: String?
     
     private var installInfo: ConcreteConstraintInstallInfo? = nil
     
-    internal init(fromItem: ConstraintItem, toItem: ConstraintItem, relation: ConstraintRelation, constant: Any, multiplier: Float, priority: Float, identifier: String? = nil) {
+    internal init(fromItem: ConstraintItem, toItem: ConstraintItem, relation: ConstraintRelation, constant: Any, multiplier: Float, priority: Float, label: String? = nil) {
         self.fromItem = fromItem
         self.toItem = toItem
         self.relation = relation
         self.constant = constant
         self.multiplier = multiplier
         self.priority = priority
-        self.identifier = identifier
+        self.label = label
     }
     
     internal func installOnView(updateExisting updateExisting: Bool = false, file: String? = nil, line: UInt? = nil) -> [LayoutConstraint] {
@@ -272,7 +272,7 @@ internal class ConcreteConstraint: Constraint {
                 attribute: layoutToAttribute,
                 multiplier: CGFloat(self.multiplier),
                 constant: layoutConstant)
-            layoutConstraint.identifier = self.identifier
+            layoutConstraint.identifier = self.label
             
             // set priority
             layoutConstraint.priority = self.priority
diff --git a/Source/ConstraintDescription.swift b/Source/ConstraintDescription.swift
index 6368fc2..6eb5492 100644
--- a/Source/ConstraintDescription.swift
+++ b/Source/ConstraintDescription.swift
@@ -34,7 +34,7 @@ public protocol ConstraintDescriptionFinalizable: class {
     
     var constraint: Constraint { get }
     
-    func identifiedAs(identifier: String) -> ConstraintDescriptionFinalizable
+    func labeled(label: String) -> ConstraintDescriptionFinalizable
     
 }
 
@@ -193,7 +193,7 @@ internal class ConstraintDescription: ConstraintDescriptionExtendable, Constrain
     internal var centerX: ConstraintDescriptionExtendable { return self.addConstraint(ConstraintAttributes.CenterX) }
     internal var centerY: ConstraintDescriptionExtendable { return self.addConstraint(ConstraintAttributes.CenterY) }
     internal var baseline: ConstraintDescriptionExtendable { return self.addConstraint(ConstraintAttributes.Baseline) }
-    internal var identifier: String?
+    internal var label: String?
     
     @available(iOS 8.0, *)
     internal var firstBaseline: ConstraintDescriptionExtendable { return self.addConstraint(ConstraintAttributes.FirstBaseline) }
@@ -491,13 +491,13 @@ internal class ConstraintDescription: ConstraintDescriptionExtendable, Constrain
                 constant: self.constant,
                 multiplier: self.multiplier,
                 priority: self.priority,
-                identifier: self.identifier)
+                label: self.label)
         }
         return self.concreteConstraint!
     }
     
-    func identifiedAs(identifier: String) -> ConstraintDescriptionFinalizable {
-        self.identifier = identifier
+    func labeled(label: String) -> ConstraintDescriptionFinalizable {
+        self.label = label
         return self
     }
     
diff --git a/Tests/Tests.swift b/Tests/Tests.swift
index 7aa81c0..eea55b9 100644
--- a/Tests/Tests.swift
+++ b/Tests/Tests.swift
@@ -255,7 +255,7 @@ class SnapKitTests: XCTestCase {
         self.container.addSubview(view)
         
         view.snp_makeConstraints { (make) -> Void in
-            make.top.equalTo(self.container.snp_top).identifiedAs(identifier)
+            make.top.equalTo(self.container.snp_top).labeled(identifier)
         }
         
         let constraints = container.snp_constraints as! [NSLayoutConstraint]