diff --git a/src/Directory.build.targets b/src/Directory.build.targets
index 879f58c9dd..5839d7ccd6 100644
--- a/src/Directory.build.targets
+++ b/src/Directory.build.targets
@@ -1,28 +1,32 @@
 <Project>
-  <PropertyGroup Condition="'$(TargetFramework)' == 'netstandard2.0'">
-    <DefineConstants>$(DefineConstants);PORTABLE</DefineConstants>
+  <PropertyGroup Condition="$(TargetFramework.StartsWith('netstandard'))">
+    <DefineConstants>$(DefineConstants);NETSTANDARD;PORTABLE</DefineConstants>
   </PropertyGroup>
-  <PropertyGroup Condition="'$(TargetFramework)' == 'net461'">
+  <PropertyGroup Condition="$(TargetFramework.StartsWith('net4'))">
     <DefineConstants>$(DefineConstants);NET_461;XAML</DefineConstants>
   </PropertyGroup>
-  <PropertyGroup Condition="'$(TargetFramework)' == 'uap10.0.16299'">
-    <DefineConstants>$(DefineConstants);NETFX_CORE;XAML;WINDOWS_UWP</DefineConstants>
+  <PropertyGroup Condition="$(TargetFramework.StartsWith('uap'))">
+    <DefineConstants>$(DefineConstants);NETFX_CORE;XAML;WINDOWS;WINDOWS_UWP</DefineConstants>
   </PropertyGroup>
-  <PropertyGroup Condition="'$(TargetFramework)' == 'Xamarin.iOS10'">
-    <DefineConstants>$(DefineConstants);MONO;UIKIT;COCOA</DefineConstants>
+  <PropertyGroup Condition="$(TargetFramework.StartsWith('Xamarin.iOS'))">
+    <DefineConstants>$(DefineConstants);MONO;UIKIT;COCOA;IOS</DefineConstants>
   </PropertyGroup>
-   <PropertyGroup Condition="'$(TargetFramework)' == 'Xamarin.Mac20'">
-    <DefineConstants>$(DefineConstants);MONO;COCOA</DefineConstants>
+   <PropertyGroup Condition="$(TargetFramework.StartsWith('Xamarin.Mac'))">
+    <DefineConstants>$(DefineConstants);MONO;COCOA;MAC</DefineConstants>
   </PropertyGroup>
-   <PropertyGroup Condition="'$(TargetFramework)' == 'Xamarin.TVOS10'">
-    <DefineConstants>$(DefineConstants);MONO;UIKIT;COCOA;TVOS10</DefineConstants>
+   <PropertyGroup Condition="$(TargetFramework.StartsWith('Xamarin.TVOS'))">
+    <DefineConstants>$(DefineConstants);MONO;UIKIT;COCOA;TVOS</DefineConstants>
   </PropertyGroup>
-  <PropertyGroup Condition="'$(TargetFramework)' == 'MonoAndroid80'">
+  <PropertyGroup Condition="$(TargetFramework.StartsWith('Xamarin.WatchOS'))">
+    <DefineConstants>$(DefineConstants);MONO;COCOA;WATCHOS</DefineConstants>
+  </PropertyGroup>
+  <PropertyGroup Condition="$(TargetFramework.StartsWith('MonoAndroid'))">
     <DefineConstants>$(DefineConstants);MONO;ANDROID</DefineConstants>
   </PropertyGroup>
-  <PropertyGroup Condition="'$(TargetFramework)' == 'netcoreapp2.0'">
+  <PropertyGroup Condition="$(TargetFramework.StartsWith('netcoreapp'))">
+    <DefineConstants>$(DefineConstants);NETCOREAPP</DefineConstants>
   </PropertyGroup>
-  <PropertyGroup Condition="'$(TargetFramework)' == 'tizen40'">
-    <DefineConstants>$(DefineConstants);Tizen</DefineConstants>
+  <PropertyGroup Condition="$(TargetFramework.StartsWith('tizen'))">
+    <DefineConstants>$(DefineConstants);TIZEN</DefineConstants>
   </PropertyGroup>
 </Project>
diff --git a/src/ReactiveUI/Platforms/apple-common/PlatformOperations.cs b/src/ReactiveUI/Platforms/apple-common/PlatformOperations.cs
index e2f6ae03ef..4738d256c5 100644
--- a/src/ReactiveUI/Platforms/apple-common/PlatformOperations.cs
+++ b/src/ReactiveUI/Platforms/apple-common/PlatformOperations.cs
@@ -11,7 +11,7 @@ public class PlatformOperations : IPlatformOperations
     {
         public string GetOrientation()
         {
-#if UIKIT && !TVOS10
+#if UIKIT && !TVOS
             return UIKit.UIDevice.CurrentDevice.Orientation.ToString();
 #else
             return null;
diff --git a/src/ReactiveUI/ReactiveUI.csproj b/src/ReactiveUI/ReactiveUI.csproj
index 0cdb8850ba..6bc9922001 100644
--- a/src/ReactiveUI/ReactiveUI.csproj
+++ b/src/ReactiveUI/ReactiveUI.csproj
@@ -14,7 +14,7 @@
     <PackageReference Include="Splat" Version="4.0.2" />
   </ItemGroup>
 
-  <ItemGroup Condition=" '$(TargetFramework)' == 'netstandard2.0' ">
+  <ItemGroup Condition=" $(TargetFramework.StartsWith('netstandard')) ">
     <Compile Include="Platforms\netstandard2.0\**\*.cs" />
     <PackageReference Include="System.ComponentModel" Version="4.3.0" />
     <PackageReference Include="System.Diagnostics.Contracts" Version="4.3.0" />
@@ -22,7 +22,7 @@
     <PackageReference Include="System.Runtime.Serialization.Primitives" Version="4.3.0" />
   </ItemGroup>
 
-  <ItemGroup Condition="'$(TargetFramework)' == 'net461'">
+  <ItemGroup Condition=" $(TargetFramework.StartsWith('net4')) ">
     <Compile Include="Platforms\net461\**\*.cs" />
     <PackageReference Include="System.ValueTuple" Version="4.5.0" />
   </ItemGroup>
@@ -31,12 +31,12 @@
     <Compile Include="Platforms\shared\**\*.cs" />
   </ItemGroup>
 
-  <ItemGroup Condition=" '$(TargetFramework)' == 'uap10.0.16299' ">
+  <ItemGroup Condition=" $(TargetFramework.StartsWith('uap')) ">
     <Compile Include="Platforms\windows-common\**\*.cs" />
     <Compile Include="Platforms\uap10.0.16299\**\*.cs" />
   </ItemGroup>
 
-  <ItemGroup Condition=" '$(TargetFramework)' == 'Xamarin.iOS10' ">
+  <ItemGroup Condition=" $(TargetFramework.StartsWith('Xamarin.iOS')) ">
     <Compile Include="Platforms\apple-common\**\*.cs" />
     <Compile Include="Platforms\ios\**\*.cs" />
     <Compile Include="Platforms\uikit-common\**\*.cs" />
@@ -44,7 +44,7 @@
     <Reference Include="System.Runtime.Serialization" />
   </ItemGroup>
 
-  <ItemGroup Condition=" '$(TargetFramework)' == 'Xamarin.Mac20' ">
+  <ItemGroup Condition=" $(TargetFramework.StartsWith('Xamarin.Mac')) ">
     <Compile Include="Platforms\apple-common\**\*.cs" />
     <Compile Include="Platforms\mac\**\*.cs" />
     <Compile Include="Platforms\xamarin-common\**\*.cs" />
@@ -52,7 +52,7 @@
     <Reference Include="netstandard" />
   </ItemGroup>
 
-    <ItemGroup Condition=" '$(TargetFramework)' == 'Xamarin.TVOS10' ">
+  <ItemGroup Condition=" $(TargetFramework.StartsWith('Xamarin.TVOS')) ">
     <Compile Include="Platforms\apple-common\**\*.cs" />
     <Compile Include="Platforms\tvos\**\*.cs" />
     <Compile Include="Platforms\uikit-common\**\*.cs" />	
@@ -60,18 +60,18 @@
     <Reference Include="System.Runtime.Serialization" />
   </ItemGroup>
 
-  <ItemGroup Condition=" '$(TargetFramework)' == 'MonoAndroid80' ">
+  <ItemGroup Condition=" $(TargetFramework.StartsWith('MonoAndroid')) ">
     <Compile Include="Platforms\android\**\*.cs" />
     <Compile Include="Platforms\xamarin-common\**\*.cs" />
     <Reference Include="System.Runtime.Serialization" />
   </ItemGroup>
 
-  <ItemGroup Condition=" '$(TargetFramework)' == 'netcoreapp2.0' ">
+  <ItemGroup Condition=" $(TargetFramework.StartsWith('netcoreapp')) ">
     <Compile Include="Platforms\netcoreapp2.0\**\*.cs" />
     <PackageReference Include="System.Runtime.Serialization.Primitives" Version="4.3.0" />
   </ItemGroup>
 
-  <ItemGroup Condition=" '$(TargetFramework)' == 'tizen40' ">
+  <ItemGroup Condition=" $(TargetFramework.StartsWith('tizen')) ">
     <Compile Include="Platforms\tizen\**\*.cs" />
     <Compile Include="Platforms\xamarin-common\**\*.cs" />
     <PackageReference Include="System.Collections" Version="4.3.0" />