diff --git a/RombaSharp/RombaSharp.csproj b/RombaSharp/RombaSharp.csproj
index 7562deed..b624adf9 100644
--- a/RombaSharp/RombaSharp.csproj
+++ b/RombaSharp/RombaSharp.csproj
@@ -8,6 +8,10 @@
     <Platforms>AnyCPU;x64</Platforms>
   </PropertyGroup>
 
+  <PropertyGroup Condition="'$(TargetFramework)'!='netcoreapp3.1'">
+    <DefineConstants>NET_FRAMEWORK</DefineConstants>
+  </PropertyGroup>
+
   <ItemGroup>
     <PackageReference Include="Mono.Data.Sqlite.Portable" Version="1.0.3.5" />
   </ItemGroup>
diff --git a/SabreTools.Library/Data/Build.cs b/SabreTools.Library/Data/Build.cs
index bf2e9822..0336aba6 100644
--- a/SabreTools.Library/Data/Build.cs
+++ b/SabreTools.Library/Data/Build.cs
@@ -8,11 +8,18 @@ namespace SabreTools.Library.Data
     public static class Build
     {
         /// <summary>
-        /// Returns true if running in a Mono environment
+        /// Returns true if running in a Mono or .NET Core environment
         /// </summary>
-        public static bool MonoEnvironment
+        public static bool MonoOrCoreEnvironment
         {
-            get { return (Type.GetType("Mono.Runtime") != null); }
+            get
+            {
+#if NET_FRAMEWORK
+                return Type.GetType("Mono.Runtime") != null;
+#else
+                return true;
+#endif
+            }
         }
 
         /// <summary>
@@ -33,7 +40,7 @@ namespace SabreTools.Library.Data
                 // Set the console to ready state
                 ConsoleColor formertext = ConsoleColor.White;
                 ConsoleColor formerback = ConsoleColor.Black;
-                if (!MonoEnvironment)
+                if (!MonoOrCoreEnvironment)
                 {
                     Console.SetBufferSize(Console.BufferWidth, 999);
                     formertext = Console.ForegroundColor;
@@ -51,7 +58,7 @@ namespace SabreTools.Library.Data
                 Console.WriteLine();
 
                 // Return the console to the original text and background colors
-                if (!MonoEnvironment)
+                if (!MonoOrCoreEnvironment)
                 {
                     Console.ForegroundColor = formertext;
                     Console.BackgroundColor = formerback;
diff --git a/SabreTools.Library/SabreTools.Library.csproj b/SabreTools.Library/SabreTools.Library.csproj
index 68665963..0e231743 100644
--- a/SabreTools.Library/SabreTools.Library.csproj
+++ b/SabreTools.Library/SabreTools.Library.csproj
@@ -7,6 +7,10 @@
     <Platforms>AnyCPU;x64</Platforms>
   </PropertyGroup>
 
+  <PropertyGroup Condition="'$(TargetFramework)'!='netcoreapp3.1'">
+    <DefineConstants>NET_FRAMEWORK</DefineConstants>
+  </PropertyGroup>
+
   <ItemGroup>
     <None Remove="Skippers\a7800.xml" />
     <None Remove="Skippers\fds.xml" />
diff --git a/SabreTools/SabreTools.csproj b/SabreTools/SabreTools.csproj
index aacdc8e5..9dd3fee1 100644
--- a/SabreTools/SabreTools.csproj
+++ b/SabreTools/SabreTools.csproj
@@ -7,6 +7,10 @@
     <Configurations>Debug;Release</Configurations>
     <Platforms>AnyCPU;x64</Platforms>
   </PropertyGroup>
+  
+  <PropertyGroup Condition="'$(TargetFramework)'!='netcoreapp3.1'">
+    <DefineConstants>NET_FRAMEWORK</DefineConstants>
+  </PropertyGroup>
 
   <ItemGroup>
     <ProjectReference Include="..\SabreTools.Library\SabreTools.Library.csproj" />