diff --git a/APIKit.xcodeproj/xcshareddata/xcschemes/APIKit-Mac.xcscheme b/APIKit.xcodeproj/xcshareddata/xcschemes/APIKit-Mac.xcscheme
index c45b3d99..ed8993c5 100644
--- a/APIKit.xcodeproj/xcshareddata/xcschemes/APIKit-Mac.xcscheme
+++ b/APIKit.xcodeproj/xcshareddata/xcschemes/APIKit-Mac.xcscheme
@@ -26,7 +26,7 @@
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
       shouldUseLaunchSchemeArgsEnv = "YES"
-      buildConfiguration = "Debug">
+      buildConfiguration = "Release">
       <Testables>
          <TestableReference
             skipped = "NO">
@@ -54,7 +54,7 @@
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
       launchStyle = "0"
       useCustomWorkingDirectory = "NO"
-      buildConfiguration = "Release"
+      buildConfiguration = "Debug"
       ignoresPersistentStateOnLaunch = "NO"
       debugDocumentVersioning = "YES"
       allowLocationSimulation = "YES">
diff --git a/circle.yml b/circle.yml
index 7648d666..d4e8bb4b 100644
--- a/circle.yml
+++ b/circle.yml
@@ -1,22 +1,25 @@
 machine:
+  xcode:
+    version: "6.3.1"
   environment:
     LC_CTYPE: en_US.UTF-8
 
 dependencies:
   override:
-    #- ./script/import-certificates
-    #- sudo gem install cocoapods
-    #- sudo gem install xcpretty
-    #- brew install carthage
-    #- carthage bootstrap
-    - echo "skip installing dependencies until Circle CI supports Xcode 6.3 (with Swift 1.2)."
+    - sudo chown :wheel "/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 7.1.simruntime/Contents/Resources/RuntimeRoot/usr/lib/dyld_sim"
+    - sudo chown :wheel "/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 8.1.simruntime/Contents/Resources/RuntimeRoot/usr/lib/dyld_sim"
+    - sudo chown :wheel "/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 8.2.simruntime/Contents/Resources/RuntimeRoot/usr/lib/dyld_sim"
+    - ./script/import-certificates
+    - sudo gem install cocoapods
+    - sudo gem install xcpretty
+    - brew update
+    - brew install carthage
+    - carthage bootstrap
 
 test:
   override:
-    #- ./script/check-carthage-compatibility
-    #- pod lib lint
-    #- set -o pipefail && xcodebuild test -scheme APIKit-iOS | xcpretty -c -r junit -o $CIRCLE_TEST_REPORTS/test-report-ios.xml
-    #- set -o pipefail && xcodebuild test -scheme APIKit-Mac | xcpretty -c -r junit -o $CIRCLE_TEST_REPORTS/test-report-mac.xml
-    #- set -o pipefail && xcodebuild build -scheme DemoApp -sdk iphonesimulator | xcpretty -c
-    - echo "skip testing until Circle CI supports Xcode 6.3 (with Swift 1.2)."
-
+    - ./script/check-carthage-compatibility
+    - pod lib lint --allow-warnings
+    - set -o pipefail && xcodebuild test -scheme APIKit-iOS | xcpretty -c -r junit -o $CIRCLE_TEST_REPORTS/test-report-ios.xml
+    - set -o pipefail && xcodebuild test -scheme APIKit-Mac | xcpretty -c -r junit -o $CIRCLE_TEST_REPORTS/test-report-mac.xml
+    - set -o pipefail && xcodebuild build -scheme DemoApp -sdk iphonesimulator | xcpretty -c