diff --git a/BUILD b/BUILD
index bdea522ad15..d3a77808ea1 100644
--- a/BUILD
+++ b/BUILD
@@ -51,9 +51,9 @@ load(
 # This should be updated along with build.yaml
 g_stands_for = "gregarious"
 
-core_version = "3.0.0-dev"
+core_version = "4.0.0-dev"
 
-version = "1.4.0-dev"
+version = "1.5.0-dev"
 
 grpc_cc_library(
     name = "gpr",
diff --git a/CMakeLists.txt b/CMakeLists.txt
index fd53f621a65..11c6b047888 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -39,7 +39,7 @@
 cmake_minimum_required(VERSION 2.8)
 
 set(PACKAGE_NAME      "grpc")
-set(PACKAGE_VERSION   "1.4.0-dev")
+set(PACKAGE_VERSION   "1.5.0-dev")
 set(PACKAGE_STRING    "${PACKAGE_NAME} ${PACKAGE_VERSION}")
 set(PACKAGE_TARNAME   "${PACKAGE_NAME}-${PACKAGE_VERSION}")
 set(PACKAGE_BUGREPORT "https://github.com/grpc/grpc/issues/")
diff --git a/Makefile b/Makefile
index 82b2104b4a7..5e29711fb18 100644
--- a/Makefile
+++ b/Makefile
@@ -423,8 +423,8 @@ Q = @
 endif
 
 CORE_VERSION = 4.0.0-dev
-CPP_VERSION = 1.4.0-dev
-CSHARP_VERSION = 1.4.0-dev
+CPP_VERSION = 1.5.0-dev
+CSHARP_VERSION = 1.5.0-dev
 
 CPPFLAGS_NO_ARCH += $(addprefix -I, $(INCLUDES)) $(addprefix -D, $(DEFINES))
 CPPFLAGS += $(CPPFLAGS_NO_ARCH) $(ARCH_FLAGS)
diff --git a/build.yaml b/build.yaml
index 26144e33def..d1e61256e6e 100644
--- a/build.yaml
+++ b/build.yaml
@@ -14,7 +14,7 @@ settings:
   '#10': See the expand_version.py for all the quirks here
   core_version: 4.0.0-dev
   g_stands_for: gregarious
-  version: 1.4.0-dev
+  version: 1.5.0-dev
 filegroups:
 - name: census
   public_headers:
diff --git a/gRPC-Core.podspec b/gRPC-Core.podspec
index d9de2d78a05..e5e61df477f 100644
--- a/gRPC-Core.podspec
+++ b/gRPC-Core.podspec
@@ -37,7 +37,7 @@
 
 Pod::Spec.new do |s|
   s.name     = 'gRPC-Core'
-  version = '1.4.0-dev'
+  version = '1.5.0-dev'
   s.version  = version
   s.summary  = 'Core cross-platform gRPC library, written in C'
   s.homepage = 'http://www.grpc.io'
diff --git a/gRPC-ProtoRPC.podspec b/gRPC-ProtoRPC.podspec
index 62cb0d11a1c..6baef288855 100644
--- a/gRPC-ProtoRPC.podspec
+++ b/gRPC-ProtoRPC.podspec
@@ -36,7 +36,7 @@
 
 Pod::Spec.new do |s|
   s.name     = 'gRPC-ProtoRPC'
-  version = '1.4.0-dev'
+  version = '1.5.0-dev'
   s.version  = version
   s.summary  = 'RPC library for Protocol Buffers, based on gRPC'
   s.homepage = 'http://www.grpc.io'
diff --git a/gRPC-RxLibrary.podspec b/gRPC-RxLibrary.podspec
index 77ceb22123c..dfccc5d16c4 100644
--- a/gRPC-RxLibrary.podspec
+++ b/gRPC-RxLibrary.podspec
@@ -36,7 +36,7 @@
 
 Pod::Spec.new do |s|
   s.name     = 'gRPC-RxLibrary'
-  version = '1.4.0-dev'
+  version = '1.5.0-dev'
   s.version  = version
   s.summary  = 'Reactive Extensions library for iOS/OSX.'
   s.homepage = 'http://www.grpc.io'
diff --git a/gRPC.podspec b/gRPC.podspec
index 10520bd3880..7f4886ab656 100644
--- a/gRPC.podspec
+++ b/gRPC.podspec
@@ -35,7 +35,7 @@
 
 Pod::Spec.new do |s|
   s.name     = 'gRPC'
-  version = '1.4.0-dev'
+  version = '1.5.0-dev'
   s.version  = version
   s.summary  = 'gRPC client library for iOS/OSX'
   s.homepage = 'http://www.grpc.io'
diff --git a/package.json b/package.json
index 1ed182ced93..a0d76c435b6 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "grpc",
-  "version": "1.4.0-dev",
+  "version": "1.5.0-dev",
   "author": "Google Inc.",
   "description": "gRPC Library for Node",
   "homepage": "http://www.grpc.io/",
diff --git a/package.xml b/package.xml
index 9179ef238c9..817a0345d60 100644
--- a/package.xml
+++ b/package.xml
@@ -13,8 +13,8 @@
  <date>2017-05-22</date>
  <time>16:06:07</time>
  <version>
-  <release>1.4.0dev</release>
-  <api>1.4.0dev</api>
+  <release>1.5.0dev</release>
+  <api>1.5.0dev</api>
  </version>
  <stability>
   <release>beta</release>
diff --git a/src/cpp/common/version_cc.cc b/src/cpp/common/version_cc.cc
index 72a4c4cf94a..e4f5cb8422e 100644
--- a/src/cpp/common/version_cc.cc
+++ b/src/cpp/common/version_cc.cc
@@ -37,5 +37,5 @@
 #include <grpc++/grpc++.h>
 
 namespace grpc {
-grpc::string Version() { return "1.4.0-dev"; }
+grpc::string Version() { return "1.5.0-dev"; }
 }
diff --git a/src/csharp/Grpc.Core/Version.csproj.include b/src/csharp/Grpc.Core/Version.csproj.include
index 8388bfd9cca..81156452f3e 100755
--- a/src/csharp/Grpc.Core/Version.csproj.include
+++ b/src/csharp/Grpc.Core/Version.csproj.include
@@ -1,7 +1,7 @@
 <!-- This file is generated -->
 <Project>
   <PropertyGroup>
-    <GrpcCsharpVersion>1.4.0-dev</GrpcCsharpVersion>
+    <GrpcCsharpVersion>1.5.0-dev</GrpcCsharpVersion>
     <GoogleProtobufVersion>3.3.0</GoogleProtobufVersion>
   </PropertyGroup>
 </Project>
diff --git a/src/csharp/Grpc.Core/VersionInfo.cs b/src/csharp/Grpc.Core/VersionInfo.cs
index 2e55d9d80eb..d507878c2df 100644
--- a/src/csharp/Grpc.Core/VersionInfo.cs
+++ b/src/csharp/Grpc.Core/VersionInfo.cs
@@ -48,11 +48,11 @@ namespace Grpc.Core
         /// <summary>
         /// Current <c>AssemblyFileVersion</c> of gRPC C# assemblies
         /// </summary>
-        public const string CurrentAssemblyFileVersion = "1.4.0.0";
+        public const string CurrentAssemblyFileVersion = "1.5.0.0";
 
         /// <summary>
         /// Current version of gRPC C#
         /// </summary>
-        public const string CurrentVersion = "1.4.0-dev";
+        public const string CurrentVersion = "1.5.0-dev";
     }
 }
diff --git a/src/csharp/build_packages_dotnetcli.bat b/src/csharp/build_packages_dotnetcli.bat
index aa8a8d3b17b..35664cc762d 100755
--- a/src/csharp/build_packages_dotnetcli.bat
+++ b/src/csharp/build_packages_dotnetcli.bat
@@ -28,7 +28,7 @@
 @rem OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 @rem Current package versions
-set VERSION=1.4.0-dev
+set VERSION=1.5.0-dev
 
 @rem Adjust the location of nuget.exe
 set NUGET=C:\nuget\nuget.exe
diff --git a/src/csharp/build_packages_dotnetcli.sh b/src/csharp/build_packages_dotnetcli.sh
index d33923845c1..7dc07a220df 100755
--- a/src/csharp/build_packages_dotnetcli.sh
+++ b/src/csharp/build_packages_dotnetcli.sh
@@ -54,7 +54,7 @@ dotnet pack --configuration Release Grpc.Auth --output ../../../artifacts
 dotnet pack --configuration Release Grpc.HealthCheck --output ../../../artifacts
 dotnet pack --configuration Release Grpc.Reflection --output ../../../artifacts
 
-nuget pack Grpc.nuspec -Version "1.4.0-dev" -OutputDirectory ../../artifacts
-nuget pack Grpc.Tools.nuspec -Version "1.4.0-dev" -OutputDirectory ../../artifacts
+nuget pack Grpc.nuspec -Version "1.5.0-dev" -OutputDirectory ../../artifacts
+nuget pack Grpc.Tools.nuspec -Version "1.5.0-dev" -OutputDirectory ../../artifacts
 
 (cd ../../artifacts && zip csharp_nugets_dotnetcli.zip *.nupkg)
diff --git a/src/node/health_check/package.json b/src/node/health_check/package.json
index 37c9b7a54f5..0922f54a394 100644
--- a/src/node/health_check/package.json
+++ b/src/node/health_check/package.json
@@ -1,6 +1,6 @@
 {
   "name": "grpc-health-check",
-  "version": "1.4.0-dev",
+  "version": "1.5.0-dev",
   "author": "Google Inc.",
   "description": "Health check service for use with gRPC",
   "repository": {
@@ -15,7 +15,7 @@
     }
   ],
   "dependencies": {
-    "grpc": "^1.4.0-dev",
+    "grpc": "^1.5.0-dev",
     "lodash": "^3.9.3",
     "google-protobuf": "^3.0.0"
   },
diff --git a/src/node/tools/package.json b/src/node/tools/package.json
index a81aa87f4bb..542d52d48bc 100644
--- a/src/node/tools/package.json
+++ b/src/node/tools/package.json
@@ -1,6 +1,6 @@
 {
   "name": "grpc-tools",
-  "version": "1.4.0-dev",
+  "version": "1.5.0-dev",
   "author": "Google Inc.",
   "description": "Tools for developing with gRPC on Node.js",
   "homepage": "http://www.grpc.io/",
diff --git a/src/objective-c/!ProtoCompiler-gRPCPlugin.podspec b/src/objective-c/!ProtoCompiler-gRPCPlugin.podspec
index 2f29058b59d..711814e7fa9 100644
--- a/src/objective-c/!ProtoCompiler-gRPCPlugin.podspec
+++ b/src/objective-c/!ProtoCompiler-gRPCPlugin.podspec
@@ -42,7 +42,7 @@ Pod::Spec.new do |s|
   # exclamation mark ensures that other "regular" pods will be able to find it as it'll be installed
   # before them.
   s.name     = '!ProtoCompiler-gRPCPlugin'
-  v = '1.4.0-dev'
+  v = '1.5.0-dev'
   s.version  = v
   s.summary  = 'The gRPC ProtoC plugin generates Objective-C files from .proto services.'
   s.description = <<-DESC
diff --git a/src/objective-c/GRPCClient/private/version.h b/src/objective-c/GRPCClient/private/version.h
index c846f4214c9..cacbce46448 100644
--- a/src/objective-c/GRPCClient/private/version.h
+++ b/src/objective-c/GRPCClient/private/version.h
@@ -38,4 +38,4 @@
 // `tools/buildgen/generate_projects.sh`.
 
 
-#define GRPC_OBJC_VERSION_STRING @"1.4.0-dev"
+#define GRPC_OBJC_VERSION_STRING @"1.5.0-dev"
diff --git a/src/php/composer.json b/src/php/composer.json
index a4fba7e4f6a..3a97e5fb414 100644
--- a/src/php/composer.json
+++ b/src/php/composer.json
@@ -2,7 +2,7 @@
   "name": "grpc/grpc-dev",
   "description": "gRPC library for PHP - for Developement use only",
   "license": "BSD-3-Clause",
-  "version": "1.4.0",
+  "version": "1.5.0",
   "require": {
     "php": ">=5.5.0",
     "google/protobuf": "^v3.3.0"
diff --git a/src/php/ext/grpc/version.h b/src/php/ext/grpc/version.h
index 993ef2de274..303a63ec364 100644
--- a/src/php/ext/grpc/version.h
+++ b/src/php/ext/grpc/version.h
@@ -35,6 +35,6 @@
 #ifndef VERSION_H
 #define VERSION_H
 
-#define PHP_GRPC_VERSION "1.4.0"
+#define PHP_GRPC_VERSION "1.5.0"
 
 #endif /* VERSION_H */
diff --git a/src/python/grpcio/grpc/_grpcio_metadata.py b/src/python/grpcio/grpc/_grpcio_metadata.py
index a0cb0dd067f..3ae2602d20c 100644
--- a/src/python/grpcio/grpc/_grpcio_metadata.py
+++ b/src/python/grpcio/grpc/_grpcio_metadata.py
@@ -29,4 +29,4 @@
 
 # AUTO-GENERATED FROM `$REPO_ROOT/templates/src/python/grpcio/grpc/_grpcio_metadata.py.template`!!!
 
-__version__ = """1.4.0.dev0"""
+__version__ = """1.5.0.dev0"""
diff --git a/src/python/grpcio/grpc_version.py b/src/python/grpcio/grpc_version.py
index ea4bc7ba207..f5bd29ff85c 100644
--- a/src/python/grpcio/grpc_version.py
+++ b/src/python/grpcio/grpc_version.py
@@ -29,4 +29,4 @@
 
 # AUTO-GENERATED FROM `$REPO_ROOT/templates/src/python/grpcio/grpc_version.py.template`!!!
 
-VERSION='1.4.0.dev0'
+VERSION='1.5.0.dev0'
diff --git a/src/python/grpcio_health_checking/grpc_version.py b/src/python/grpcio_health_checking/grpc_version.py
index 26aa555e14c..26a83018839 100644
--- a/src/python/grpcio_health_checking/grpc_version.py
+++ b/src/python/grpcio_health_checking/grpc_version.py
@@ -29,4 +29,4 @@
 
 # AUTO-GENERATED FROM `$REPO_ROOT/templates/src/python/grpcio_health_checking/grpc_version.py.template`!!!
 
-VERSION='1.4.0.dev0'
+VERSION='1.5.0.dev0'
diff --git a/src/python/grpcio_reflection/grpc_version.py b/src/python/grpcio_reflection/grpc_version.py
index 978d6b4011f..f16737df80a 100644
--- a/src/python/grpcio_reflection/grpc_version.py
+++ b/src/python/grpcio_reflection/grpc_version.py
@@ -29,4 +29,4 @@
 
 # AUTO-GENERATED FROM `$REPO_ROOT/templates/src/python/grpcio_reflection/grpc_version.py.template`!!!
 
-VERSION='1.4.0.dev0'
+VERSION='1.5.0.dev0'
diff --git a/src/python/grpcio_tests/grpc_version.py b/src/python/grpcio_tests/grpc_version.py
index 5f0b0848846..28cf8a8a628 100644
--- a/src/python/grpcio_tests/grpc_version.py
+++ b/src/python/grpcio_tests/grpc_version.py
@@ -29,4 +29,4 @@
 
 # AUTO-GENERATED FROM `$REPO_ROOT/templates/src/python/grpcio_tests/grpc_version.py.template`!!!
 
-VERSION='1.4.0.dev0'
+VERSION='1.5.0.dev0'
diff --git a/src/ruby/lib/grpc/version.rb b/src/ruby/lib/grpc/version.rb
index f30dff335f1..e2e784d19f2 100644
--- a/src/ruby/lib/grpc/version.rb
+++ b/src/ruby/lib/grpc/version.rb
@@ -29,5 +29,5 @@
 
 # GRPC contains the General RPC module.
 module GRPC
-  VERSION = '1.4.0.dev'
+  VERSION = '1.5.0.dev'
 end
diff --git a/src/ruby/tools/version.rb b/src/ruby/tools/version.rb
index 1f8d4afb95f..4f74238df79 100644
--- a/src/ruby/tools/version.rb
+++ b/src/ruby/tools/version.rb
@@ -29,6 +29,6 @@
 
 module GRPC
   module Tools
-    VERSION = '1.4.0.dev'
+    VERSION = '1.5.0.dev'
   end
 end
diff --git a/tools/distrib/python/grpcio_tools/grpc_version.py b/tools/distrib/python/grpcio_tools/grpc_version.py
index 1f2aa81c850..417722a4d24 100644
--- a/tools/distrib/python/grpcio_tools/grpc_version.py
+++ b/tools/distrib/python/grpcio_tools/grpc_version.py
@@ -29,4 +29,4 @@
 
 # AUTO-GENERATED FROM `$REPO_ROOT/templates/tools/distrib/python/grpcio_tools/grpc_version.py.template`!!!
 
-VERSION='1.4.0.dev0'
+VERSION='1.5.0.dev0'
diff --git a/tools/doxygen/Doxyfile.c++ b/tools/doxygen/Doxyfile.c++
index 3861bdb85af..23746de1aa5 100644
--- a/tools/doxygen/Doxyfile.c++
+++ b/tools/doxygen/Doxyfile.c++
@@ -40,7 +40,7 @@ PROJECT_NAME           = "GRPC C++"
 # could be handy for archiving the generated documentation or if some version
 # control system is used.
 
-PROJECT_NUMBER         = 1.4.0-dev
+PROJECT_NUMBER         = 1.5.0-dev
 
 # Using the PROJECT_BRIEF tag one can provide an optional one line description
 # for a project that appears at the top of each page and should give viewer a
diff --git a/tools/doxygen/Doxyfile.c++.internal b/tools/doxygen/Doxyfile.c++.internal
index 5bab66c7d6a..52e722f56c9 100644
--- a/tools/doxygen/Doxyfile.c++.internal
+++ b/tools/doxygen/Doxyfile.c++.internal
@@ -40,7 +40,7 @@ PROJECT_NAME           = "GRPC C++"
 # could be handy for archiving the generated documentation or if some version
 # control system is used.
 
-PROJECT_NUMBER         = 1.4.0-dev
+PROJECT_NUMBER         = 1.5.0-dev
 
 # Using the PROJECT_BRIEF tag one can provide an optional one line description
 # for a project that appears at the top of each page and should give viewer a