diff --git a/Library/Homebrew/os/mac.rb b/Library/Homebrew/os/mac.rb
index 1c014d9340..6dd281ce74 100644
--- a/Library/Homebrew/os/mac.rb
+++ b/Library/Homebrew/os/mac.rb
@@ -211,6 +211,7 @@ module OS
       "6.1"   => { :clang => "6.0", :clang_build => 600 },
       "6.1.1" => { :clang => "6.0", :clang_build => 600 },
       "6.2"   => { :clang => "6.0", :clang_build => 600 },
+      "6.3"   => { :clang => "6.1", :clang_build => 602 },
     }
 
     def compilers_standard?
diff --git a/Library/Homebrew/os/mac/xcode.rb b/Library/Homebrew/os/mac/xcode.rb
index 23b1194e1c..2814f8c9fb 100644
--- a/Library/Homebrew/os/mac/xcode.rb
+++ b/Library/Homebrew/os/mac/xcode.rb
@@ -14,11 +14,11 @@ module OS
         when "10.7"  then "4.6.3"
         when "10.8"  then "5.1.1"
         when "10.9"  then "6.2"
-        when "10.10" then "6.2"
+        when "10.10" then "6.3"
         else
           # Default to newest known version of Xcode for unreleased OSX versions.
           if MacOS.version > "10.10"
-            "6.2"
+            "6.3"
           else
             raise "Mac OS X '#{MacOS.version}' is invalid"
           end
@@ -117,7 +117,8 @@ module OS
           when 50      then "5.0"
           when 51      then "5.1"
           when 60      then "6.0"
-          else "6.0"
+          when 61      then "6.1"
+          else "6.1"
           end
         end
       end
@@ -160,7 +161,7 @@ module OS
 
       def latest_version
         case MacOS.version
-        when "10.10" then "600.0.57"
+        when "10.10" then "602.0.49"
         when "10.9"  then "600.0.57"
         when "10.8"  then "503.0.40"
         else