diff --git a/.travis.yml b/.travis.yml
index a3ae7e3..505b5bc 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,13 +5,15 @@ os:
 language: generic
 sudo: required
 dist: trusty
-osx_image: xcode10.2
+osx_image: xcode12.2
 env:
-  - BUILD="pushd Examples && pod repo update && pod install && set -o pipefail && (xcodebuild -workspace   Examples.xcworkspace   -scheme Example -destination 'platform=iOS Simulator,name=iPhone 7' build) | xcpretty"
+  - BUILD="pushd Examples && pod repo update && pod install && set -o pipefail && (xcodebuild -workspace Examples.xcworkspace -scheme Example -destination 'platform=iOS Simulator,name=iPhone 12' build) | xcpretty"
   - BUILD="pod repo update && pod lib lint RxFeedback.podspec --verbose"
   - BUILD="swift build"
-  - BUILD="carthage update --platform ios && carthage build --no-skip-current --platform iOS && set -o pipefail && (xcodebuild -project RxFeedback.xcodeproj   -scheme RxFeedbackTests -destination 'platform=iOS Simulator,name=iPhone 7' test) | xcpretty"
-  - BUILD="carthage update --platform tvOS && carthage build --no-skip-current --platform tvOS"
+
+  # Carthage is still broken for Xcode 12, until support for XCFrameworks is added
+  # - BUILD="carthage update --platform ios && carthage build --no-skip-current --platform iOS && set -o pipefail && (xcodebuild -project RxFeedback.xcodeproj   -scheme RxFeedbackTests -destination 'platform=iOS Simulator,name=iPhone 7' test) | xcpretty"
+  # - BUILD="carthage update --platform tvOS && carthage build --no-skip-current --platform tvOS"
 
 script: eval "${BUILD}"
 
diff --git a/Examples/Examples.xcworkspace/contents.xcworkspacedata b/Examples/Examples.xcworkspace/contents.xcworkspacedata
new file mode 100644
index 0000000..0a69e11
--- /dev/null
+++ b/Examples/Examples.xcworkspace/contents.xcworkspacedata
@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Workspace
+   version = "1.0">
+   <FileRef
+      location = "group:Examples.xcodeproj">
+   </FileRef>
+   <FileRef
+      location = "group:Pods/Pods.xcodeproj">
+   </FileRef>
+</Workspace>
diff --git a/Examples/Examples.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist b/Examples/Examples.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist
new file mode 100644
index 0000000..18d9810
--- /dev/null
+++ b/Examples/Examples.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>IDEDidComputeMac32BitWarning</key>
+	<true/>
+</dict>
+</plist>
diff --git a/Examples/Examples/GithubPaginatedSearch.swift b/Examples/Examples/GithubPaginatedSearch.swift
index 11cb1de..f71ab9c 100644
--- a/Examples/Examples/GithubPaginatedSearch.swift
+++ b/Examples/Examples/GithubPaginatedSearch.swift
@@ -220,7 +220,7 @@ extension URLSession {
             .response(request: URLRequest(url: resource))
             .retry(3)
             .map(Repository.parse)
-            .retryWhen { errorTrigger in
+            .retry(when: { errorTrigger in
                 return errorTrigger.enumerated().flatMap { (attempt, error) -> Observable<Int> in
                     if attempt >= maxAttempts - 1 {
                         return Observable.error(error)
@@ -229,7 +229,7 @@ extension URLSession {
                     return Observable<Int>
                         .timer(.milliseconds((attempt + 1) * 1000), scheduler: MainScheduler.instance).take(1)
                 }
-        }
+            })
     }
 }
 
diff --git a/Examples/Examples/Todo+UI.swift b/Examples/Examples/Todo+UI.swift
index 63bcedc..92e3df5 100644
--- a/Examples/Examples/Todo+UI.swift
+++ b/Examples/Examples/Todo+UI.swift
@@ -28,7 +28,7 @@ class TodoViewController: UIViewController {
         // this dependency would be ideally injected in some way
         let synchronize: (Task) -> Single<SyncState> = { task in
             return Single<SyncState>.create { single in
-                    let state: SingleEvent<SyncState> = arc4random_uniform(3) != 0 ? .success(.success) : .error(SystemError(""))
+                    let state: SingleEvent<SyncState> = arc4random_uniform(3) != 0 ? .success(.success) : .failure(SystemError(""))
                     single(state)
                     return Disposables.create()
                 }
diff --git a/Examples/Podfile.lock b/Examples/Podfile.lock
new file mode 100644
index 0000000..4db28e8
--- /dev/null
+++ b/Examples/Podfile.lock
@@ -0,0 +1,33 @@
+PODS:
+  - RxCocoa (6.0.0):
+    - RxRelay (= 6.0.0)
+    - RxSwift (= 6.0.0)
+  - RxFeedback (4.0.0):
+    - RxCocoa (~> 6.0)
+    - RxSwift (~> 6.0)
+  - RxRelay (6.0.0):
+    - RxSwift (= 6.0.0)
+  - RxSwift (6.0.0)
+
+DEPENDENCIES:
+  - RxFeedback (from `..`)
+
+SPEC REPOS:
+  trunk:
+    - RxCocoa
+    - RxRelay
+    - RxSwift
+
+EXTERNAL SOURCES:
+  RxFeedback:
+    :path: ".."
+
+SPEC CHECKSUMS:
+  RxCocoa: 3f79328fafa3645b34600f37c31e64c73ae3a80e
+  RxFeedback: c762a59b678ed8e30b5c84b6e4e03ad0341d2ecb
+  RxRelay: 8d593be109c06ea850df027351beba614b012ffb
+  RxSwift: c14e798c59b9f6e9a2df8fd235602e85cc044295
+
+PODFILE CHECKSUM: 1c64147e23f9070efe02f93aa36b8029d82c504e
+
+COCOAPODS: 1.10.0
diff --git a/RxFeedback.podspec b/RxFeedback.podspec
index e703ee8..416d2c2 100644
--- a/RxFeedback.podspec
+++ b/RxFeedback.podspec
@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name         = "RxFeedback"
-  s.version      = "3.0.0"
+  s.version      = "4.0.0"
   s.summary      = "Simplest architecture for RxSwift. State + feedback loops."
   s.description  = <<-DESC
     * Straightforward