diff --git a/Cartography.xcodeproj/project.pbxproj b/Cartography.xcodeproj/project.pbxproj
index 9880801..41969ff 100644
--- a/Cartography.xcodeproj/project.pbxproj
+++ b/Cartography.xcodeproj/project.pbxproj
@@ -728,6 +728,7 @@
 				);
 				INFOPLIST_FILE = Cartography/Info.plist;
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
+				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = "com.robertboehnke.${PRODUCT_NAME:rfc1034identifier}";
 				PRODUCT_NAME = Cartography;
@@ -753,6 +754,7 @@
 				);
 				INFOPLIST_FILE = Cartography/Info.plist;
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
+				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = "com.robertboehnke.${PRODUCT_NAME:rfc1034identifier}";
 				PRODUCT_NAME = Cartography;
diff --git a/Cartography/Constrain.swift b/Cartography/Constrain.swift
index 29103d1..ee55147 100644
--- a/Cartography/Constrain.swift
+++ b/Cartography/Constrain.swift
@@ -117,8 +117,17 @@ public func constrain(views: [View], replace group: ConstraintGroup = Constraint
 ///
 public func constrain<T: Hashable>(views: [T: View], replace group: ConstraintGroup = ConstraintGroup(), @noescape block: ([T : LayoutProxy] -> ())) -> ConstraintGroup {
     let context = Context()
-    let proxies = views.map { ($0, LayoutProxy(context, $1)) }
-    block(Dictionary(proxies))
+    
+    // this conflict with ObjectMapper Dictionary extension
+//    let proxies = views.map { ($0, LayoutProxy(context, $1)) }
+    
+    var proxies = [T : LayoutProxy]()
+    
+    for view in views {
+        proxies.updateValue(LayoutProxy(context, view.1), forKey: view.0)
+    }
+    
+    block(proxies)
     group.replaceConstraints(context.constraints)
 
     return group
diff --git a/README.md b/README.md
index c25f4ca..b3e38b2 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,8 @@
 # Cartography :iphone::triangular_ruler:
 
+## IOS 7 Support
+This fork is mainly for IOS 7 support, for how to use Swift pods visit  [IOS 7 Support](https://github.com/tonyli508/ForkmanForSwiftPodsWithIOS7)
+
 <a href="https://travis-ci.org/robb/Cartography?branch=master">
     <img src="https://travis-ci.org/robb/Cartography.svg?branch=master" hspace="6px" align="right" vspace="2px">
 </a>