diff --git a/Preprocessor/Preprocessor.xcodeproj/project.pbxproj b/Preprocessor/Preprocessor.xcodeproj/project.pbxproj
index e4a4e1bd..da1fd534 100644
--- a/Preprocessor/Preprocessor.xcodeproj/project.pbxproj
+++ b/Preprocessor/Preprocessor.xcodeproj/project.pbxproj
@@ -169,7 +169,7 @@
 				ONLY_ACTIVE_ARCH = YES;
 				SDKROOT = macosx;
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.0;
 			};
 			name = Debug;
 		};
@@ -208,7 +208,7 @@
 				MTL_ENABLE_DEBUG_INFO = NO;
 				SDKROOT = macosx;
 				SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.0;
 			};
 			name = Release;
 		};
diff --git a/Rx.xcodeproj/project.pbxproj b/Rx.xcodeproj/project.pbxproj
index 97e989c8..aaaaa3da 100644
--- a/Rx.xcodeproj/project.pbxproj
+++ b/Rx.xcodeproj/project.pbxproj
@@ -6154,7 +6154,7 @@
 				OTHER_SWIFT_FLAGS = "-D TRACE_RESOURCES";
 				SDKROOT = "";
 				SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 				TVOS_DEPLOYMENT_TARGET = 9.0;
 				VALIDATE_PRODUCT = YES;
@@ -6563,7 +6563,7 @@
 				OTHER_SWIFT_FLAGS = "-D TRACE_RESOURCES -D DEBUG -Xfrontend -debug-time-function-bodies";
 				SDKROOT = "";
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 				TVOS_DEPLOYMENT_TARGET = 9.0;
 				VERSIONING_SYSTEM = "apple-generic";
@@ -6615,7 +6615,7 @@
 				OTHER_SWIFT_FLAGS = "-D RELEASE";
 				SDKROOT = "";
 				SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 				TVOS_DEPLOYMENT_TARGET = 9.0;
 				VALIDATE_PRODUCT = YES;
@@ -6678,7 +6678,6 @@
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SDKROOT = iphoneos;
 				SWIFT_ACTIVE_COMPILATION_CONDITIONS = DEBUG;
-				SWIFT_VERSION = 3.0;
 			};
 			name = Debug;
 		};
@@ -6695,7 +6694,6 @@
 				PRODUCT_BUNDLE_IDENTIFIER = io.rx.Benchmarks;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SDKROOT = iphoneos;
-				SWIFT_VERSION = 3.0;
 			};
 			name = Release;
 		};
@@ -6712,7 +6710,6 @@
 				PRODUCT_BUNDLE_IDENTIFIER = io.rx.Benchmarks;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SDKROOT = iphoneos;
-				SWIFT_VERSION = 3.0;
 			};
 			name = "Release-Tests";
 		};
diff --git a/RxBlocking.podspec b/RxBlocking.podspec
index 537ca606..f7619cdf 100644
--- a/RxBlocking.podspec
+++ b/RxBlocking.podspec
@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name             = "RxBlocking"
-  s.version          = "3.5.0"
+  s.version          = "4.0.0-alpha.0"
   s.summary          = "RxSwift Blocking operatos"
   s.description      = <<-DESC
 Set of blocking operators for RxSwift. These operators are mostly intended for unit/integration tests
@@ -25,5 +25,5 @@ Waiting for observable sequence to complete before exiting command line applicat
   s.source_files          = 'RxBlocking/**/*.swift', 'Platform/**/*.swift'
   s.exclude_files         = 'RxBlocking/Platform/**/*.swift'
 
-  s.dependency 'RxSwift', '~> 3.4'
+  s.dependency 'RxSwift', '~> 4.0.0-alpha.0'
 end
diff --git a/RxBlocking/Info.plist b/RxBlocking/Info.plist
index 2bf762f6..c9490d98 100644
Binary files a/RxBlocking/Info.plist and b/RxBlocking/Info.plist differ
diff --git a/RxCocoa.podspec b/RxCocoa.podspec
index e94f3130..57e3aaeb 100644
--- a/RxCocoa.podspec
+++ b/RxCocoa.podspec
@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name             = "RxCocoa"
-  s.version          = "3.5.0"
+  s.version          = "4.0.0-alpha.0"
   s.summary          = "RxSwift Cocoa extensions"
   s.description      = <<-DESC
 * UI extensions
@@ -27,5 +27,5 @@ Pod::Spec.new do |s|
   s.watchos.source_files  = 'RxCocoa/iOS/**/*.swift'
   s.tvos.source_files     = 'RxCocoa/iOS/**/*.swift'
 
-  s.dependency 'RxSwift', '~> 3.4'
+  s.dependency 'RxSwift', '~> 4.0.0-alpha.0'
 end
diff --git a/RxCocoa/Info.plist b/RxCocoa/Info.plist
index 2bf762f6..c9490d98 100644
Binary files a/RxCocoa/Info.plist and b/RxCocoa/Info.plist differ
diff --git a/RxExample/RxExample.xcodeproj/project.pbxproj b/RxExample/RxExample.xcodeproj/project.pbxproj
index 61758725..2cf0b333 100644
--- a/RxExample/RxExample.xcodeproj/project.pbxproj
+++ b/RxExample/RxExample.xcodeproj/project.pbxproj
@@ -1671,7 +1671,6 @@
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SDKROOT = macosx;
 				SWIFT_ACTIVE_COMPILATION_CONDITIONS = DEBUG;
-				SWIFT_VERSION = 3.0;
 				TEST_TARGET_NAME = "RxExample-OSX";
 			};
 			name = Debug;
@@ -1694,7 +1693,6 @@
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SDKROOT = macosx;
 				SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";
-				SWIFT_VERSION = 3.0;
 				TEST_TARGET_NAME = "RxExample-OSX";
 			};
 			name = Release;
@@ -1717,7 +1715,6 @@
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SDKROOT = macosx;
 				SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";
-				SWIFT_VERSION = 3.0;
 				TEST_TARGET_NAME = "RxExample-OSX";
 			};
 			name = "Release-Tests";
@@ -1771,7 +1768,7 @@
 				PRODUCT_NAME = RxExample;
 				SDKROOT = "";
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
 			name = Debug;
@@ -1816,7 +1813,7 @@
 				OTHER_SWIFT_FLAGS = "-D RELEASE";
 				PRODUCT_NAME = RxExample;
 				SDKROOT = "";
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 				VALIDATE_PRODUCT = YES;
 			};
@@ -1947,7 +1944,6 @@
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SDKROOT = iphoneos;
 				SWIFT_ACTIVE_COMPILATION_CONDITIONS = DEBUG;
-				SWIFT_VERSION = 3.0;
 				TEST_TARGET_NAME = "RxExample-iOS";
 			};
 			name = Debug;
@@ -1968,7 +1964,6 @@
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SDKROOT = iphoneos;
 				SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";
-				SWIFT_VERSION = 3.0;
 				TEST_TARGET_NAME = "RxExample-iOS";
 			};
 			name = Release;
@@ -1989,7 +1984,6 @@
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SDKROOT = iphoneos;
 				SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";
-				SWIFT_VERSION = 3.0;
 				TEST_TARGET_NAME = "RxExample-iOS";
 			};
 			name = "Release-Tests";
@@ -2035,7 +2029,7 @@
 				OTHER_SWIFT_FLAGS = "-D TRACE_RESOURCES";
 				PRODUCT_NAME = RxExample;
 				SDKROOT = "";
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 				VALIDATE_PRODUCT = YES;
 			};
diff --git a/RxSwift.podspec b/RxSwift.podspec
index afb668e7..15d9c425 100644
--- a/RxSwift.podspec
+++ b/RxSwift.podspec
@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name             = "RxSwift"
-  s.version          = "3.5.0"
+  s.version          = "4.0.0-alpha.0"
   s.summary          = "RxSwift is a Swift implementation of Reactive Extensions"
   s.description      = <<-DESC
 This is a Swift port of [ReactiveX.io](https://github.com/ReactiveX)
diff --git a/RxSwift/Info.plist b/RxSwift/Info.plist
index 2bf762f6..c9490d98 100644
Binary files a/RxSwift/Info.plist and b/RxSwift/Info.plist differ
diff --git a/RxTest.podspec b/RxTest.podspec
index 6ddc2150..883860e5 100644
--- a/RxTest.podspec
+++ b/RxTest.podspec
@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name             = "RxTest"
-  s.version          = "3.5.0"
+  s.version          = "4.0.0-alpha.0"
   s.summary          = "RxSwift Testing extensions"
   s.description      = <<-DESC
 Unit testing extensions for RxSwift. This library contains mock schedulers, observables, and observers
@@ -56,7 +56,7 @@ func testMap() {
 
   s.framework    = 'XCTest'
 
-  s.dependency 'RxSwift', '~> 3.4'
+  s.dependency 'RxSwift', '~> 4.0.0-alpha.0'
 
   s.pod_target_xcconfig = { 'ENABLE_BITCODE' => 'NO' }
 end
diff --git a/RxTest/Info.plist b/RxTest/Info.plist
index 2bf762f6..c9490d98 100644
Binary files a/RxTest/Info.plist and b/RxTest/Info.plist differ