diff --git a/build/common.props b/build/common.props
index 2bd16a7b97..e9fa82d8ef 100644
--- a/build/common.props
+++ b/build/common.props
@@ -1,4 +1,5 @@
 <Project>
+  <Import Project="dependencies.props" />
   <Import Project="..\version.props" />
 
   <PropertyGroup>
@@ -8,8 +9,6 @@
     <AssemblyOriginatorKeyFile>$(MSBuildThisFileDirectory)Key.snk</AssemblyOriginatorKeyFile>
     <SignAssembly>true</SignAssembly>
     <PublicSign Condition="'$(OS)' != 'Windows_NT'">true</PublicSign>
-    <NetCoreAppImplicitPackageVersion>1.2.0-*</NetCoreAppImplicitPackageVersion>
-    <NetStandardImplicitPackageVersion>1.6.2-*</NetStandardImplicitPackageVersion>
     <VersionSuffix Condition="'$(VersionSuffix)'!='' AND '$(BuildNumber)' != ''">$(VersionSuffix)-$(BuildNumber)</VersionSuffix>
   </PropertyGroup>
 
@@ -21,4 +20,4 @@
     <PackageReference Include="NETStandard.Library" Version="$(NetStandardImplicitPackageVersion)" />
   </ItemGroup>
 
-</Project>
\ No newline at end of file
+</Project>
diff --git a/build/dependencies.props b/build/dependencies.props
new file mode 100644
index 0000000000..e704edaec0
--- /dev/null
+++ b/build/dependencies.props
@@ -0,0 +1,6 @@
+<Project>
+  <PropertyGroup>
+    <NetStandardImplicitPackageVersion>1.6.1</NetStandardImplicitPackageVersion>
+    <CoreFxVersion>4.3.0</CoreFxVersion>
+  </PropertyGroup>
+</Project>
diff --git a/src/Microsoft.AspNetCore.Http.Abstractions/Microsoft.AspNetCore.Http.Abstractions.csproj b/src/Microsoft.AspNetCore.Http.Abstractions/Microsoft.AspNetCore.Http.Abstractions.csproj
index b8ab908f72..46ec27b4f7 100644
--- a/src/Microsoft.AspNetCore.Http.Abstractions/Microsoft.AspNetCore.Http.Abstractions.csproj
+++ b/src/Microsoft.AspNetCore.Http.Abstractions/Microsoft.AspNetCore.Http.Abstractions.csproj
@@ -16,10 +16,10 @@ Microsoft.AspNetCore.Http.HttpResponse</Description>
     <ProjectReference Include="..\Microsoft.AspNetCore.Http.Features\Microsoft.AspNetCore.Http.Features.csproj" />
     <PackageReference Include="Microsoft.Extensions.ActivatorUtilities.Sources" Version="1.2.0-*" PrivateAssets="All" />
     <PackageReference Include="Microsoft.Extensions.TaskCache.Sources" Version="1.2.0-*" PrivateAssets="All" />
-    <PackageReference Include="System.Text.Encodings.Web" Version="4.4.0-*" />
+    <PackageReference Include="System.Text.Encodings.Web" Version="$(CoreFxVersion)" />
   </ItemGroup>
   <ItemGroup Condition=" '$(TargetFramework)' == 'netstandard1.3' ">
-    <PackageReference Include="System.Globalization.Extensions" Version="4.4.0-*" />
-    <PackageReference Include="System.Reflection.TypeExtensions" Version="4.4.0-*" />
+    <PackageReference Include="System.Globalization.Extensions" Version="$(CoreFxVersion)" />
+    <PackageReference Include="System.Reflection.TypeExtensions" Version="$(CoreFxVersion)" />
   </ItemGroup>
-</Project>
\ No newline at end of file
+</Project>
diff --git a/src/Microsoft.AspNetCore.Http.Extensions/Microsoft.AspNetCore.Http.Extensions.csproj b/src/Microsoft.AspNetCore.Http.Extensions/Microsoft.AspNetCore.Http.Extensions.csproj
index f5cee38563..b5b52b4694 100644
--- a/src/Microsoft.AspNetCore.Http.Extensions/Microsoft.AspNetCore.Http.Extensions.csproj
+++ b/src/Microsoft.AspNetCore.Http.Extensions/Microsoft.AspNetCore.Http.Extensions.csproj
@@ -11,6 +11,6 @@
     <ProjectReference Include="..\Microsoft.AspNetCore.Http.Abstractions\Microsoft.AspNetCore.Http.Abstractions.csproj" />
     <ProjectReference Include="..\Microsoft.Net.Http.Headers\Microsoft.Net.Http.Headers.csproj" />
     <PackageReference Include="Microsoft.Extensions.FileProviders.Abstractions" Version="1.2.0-*" />
-    <PackageReference Include="System.Buffers" Version="4.4.0-*" />
+    <PackageReference Include="System.Buffers" Version="$(CoreFxVersion)" />
   </ItemGroup>
-</Project>
\ No newline at end of file
+</Project>
diff --git a/src/Microsoft.AspNetCore.Http.Features/Microsoft.AspNetCore.Http.Features.csproj b/src/Microsoft.AspNetCore.Http.Features/Microsoft.AspNetCore.Http.Features.csproj
index d5077d39f6..7774fd2b34 100644
--- a/src/Microsoft.AspNetCore.Http.Features/Microsoft.AspNetCore.Http.Features.csproj
+++ b/src/Microsoft.AspNetCore.Http.Features/Microsoft.AspNetCore.Http.Features.csproj
@@ -9,11 +9,11 @@
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="Microsoft.Extensions.Primitives" Version="1.2.0-*" />
-    <PackageReference Include="System.ComponentModel" Version="4.4.0-*" />
-    <PackageReference Include="System.Security.Principal" Version="4.4.0-*" />
+    <PackageReference Include="System.ComponentModel" Version="$(CoreFxVersion)" />
+    <PackageReference Include="System.Security.Principal" Version="$(CoreFxVersion)" />
   </ItemGroup>
   <ItemGroup Condition=" '$(TargetFramework)' == 'netstandard1.3' ">
-    <PackageReference Include="System.Security.Claims" Version="4.4.0-*" />
-    <PackageReference Include="System.Net.WebSockets" Version="4.4.0-*" />
+    <PackageReference Include="System.Security.Claims" Version="$(CoreFxVersion)" />
+    <PackageReference Include="System.Net.WebSockets" Version="$(CoreFxVersion)" />
   </ItemGroup>
-</Project>
\ No newline at end of file
+</Project>
diff --git a/src/Microsoft.AspNetCore.Http/Microsoft.AspNetCore.Http.csproj b/src/Microsoft.AspNetCore.Http/Microsoft.AspNetCore.Http.csproj
index c3cf6b7e5d..2b41f9cd4c 100644
--- a/src/Microsoft.AspNetCore.Http/Microsoft.AspNetCore.Http.csproj
+++ b/src/Microsoft.AspNetCore.Http/Microsoft.AspNetCore.Http.csproj
@@ -15,6 +15,6 @@
     <PackageReference Include="Microsoft.Extensions.ObjectPool" Version="1.2.0-*" />
     <PackageReference Include="Microsoft.Extensions.Options" Version="1.2.0-*" />
     <PackageReference Include="Microsoft.Extensions.TaskCache.Sources" Version="1.2.0-*" PrivateAssets="All" />
-    <PackageReference Include="System.Buffers" Version="4.4.0-*" />
+    <PackageReference Include="System.Buffers" Version="$(CoreFxVersion)" />
   </ItemGroup>
-</Project>
\ No newline at end of file
+</Project>
diff --git a/src/Microsoft.AspNetCore.WebUtilities/Microsoft.AspNetCore.WebUtilities.csproj b/src/Microsoft.AspNetCore.WebUtilities/Microsoft.AspNetCore.WebUtilities.csproj
index 3a67092d21..7c069cbd84 100644
--- a/src/Microsoft.AspNetCore.WebUtilities/Microsoft.AspNetCore.WebUtilities.csproj
+++ b/src/Microsoft.AspNetCore.WebUtilities/Microsoft.AspNetCore.WebUtilities.csproj
@@ -11,6 +11,6 @@
   <ItemGroup>
     <ProjectReference Include="..\Microsoft.Net.Http.Headers\Microsoft.Net.Http.Headers.csproj" />
     <PackageReference Include="Microsoft.Extensions.WebEncoders.Sources" Version="1.2.0-*" PrivateAssets="All" />
-    <PackageReference Include="System.Text.Encodings.Web" Version="4.4.0-*" />
+    <PackageReference Include="System.Text.Encodings.Web" Version="$(CoreFxVersion)" />
   </ItemGroup>
-</Project>
\ No newline at end of file
+</Project>
diff --git a/src/Microsoft.Net.Http.Headers/Microsoft.Net.Http.Headers.csproj b/src/Microsoft.Net.Http.Headers/Microsoft.Net.Http.Headers.csproj
index 1a632944aa..358bcbf3e4 100644
--- a/src/Microsoft.Net.Http.Headers/Microsoft.Net.Http.Headers.csproj
+++ b/src/Microsoft.Net.Http.Headers/Microsoft.Net.Http.Headers.csproj
@@ -10,7 +10,7 @@
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="Microsoft.Extensions.Primitives" Version="1.2.0-*" />
-    <PackageReference Include="System.Buffers" Version="4.4.0-*" />
-    <PackageReference Include="System.Diagnostics.Contracts" Version="4.4.0-*" />
+    <PackageReference Include="System.Buffers" Version="$(CoreFxVersion)" />
+    <PackageReference Include="System.Diagnostics.Contracts" Version="$(CoreFxVersion)" />
   </ItemGroup>
-</Project>
\ No newline at end of file
+</Project>