diff --git a/source/Calamari.Common/Features/Scripting/DotnetScript/DotnetScriptExecutor.cs b/source/Calamari.Common/Features/Scripting/DotnetScript/DotnetScriptExecutor.cs
index 1df9532fc5..9e783acafd 100644
--- a/source/Calamari.Common/Features/Scripting/DotnetScript/DotnetScriptExecutor.cs
+++ b/source/Calamari.Common/Features/Scripting/DotnetScript/DotnetScriptExecutor.cs
@@ -11,6 +11,8 @@ namespace Calamari.Common.Features.Scripting.DotnetScript
 {
     public class DotnetScriptExecutor : ScriptExecutor
     {
+        const string DotnetRollForwardVariableName = "DOTNET_ROLL_FORWARD";
+
         readonly ICommandLineRunner commandLineRunner;
 
         public DotnetScriptExecutor(ICommandLineRunner commandLineRunner, ILog log): base(log)
@@ -37,13 +39,37 @@ protected override IEnumerable<ScriptExecution> PrepareExecution(Script script,
             bool.TryParse(variables.Get("Octopus.Action.Script.CSharp.BypassIsolation", "false"), out var bypassDotnetScriptIsolation);
 
             var cli = CreateCommandLineInvocation(executable, arguments, !string.IsNullOrWhiteSpace(localDotnetScriptPath));
-            cli.EnvironmentVars = environmentVars;
+            cli.EnvironmentVars = WithDotnetRollForward(environmentVars);
             cli.WorkingDirectory = workingDirectory;
             cli.Isolate = !bypassDotnetScriptIsolation;
 
             yield return new ScriptExecution(cli, otherTemporaryFiles.Concat(new[] { bootstrapFile, configurationFile }));
         }
         
+        /// <summary>
+        /// dotnet-script is a framework-dependent application - the bundled copy targets
+        /// Microsoft.NETCore.App 8.0.0. By default a framework-dependent app will not roll forward
+        /// across a major version, so on a machine that only has a newer runtime installed it fails
+        /// to launch with "You must install or update .NET to run this application".
+        ///
+        /// Calamari itself is published self-contained and carries no such requirement; this affects
+        /// only the separate dotnet-script process. Setting DOTNET_ROLL_FORWARD=Major lets it run on
+        /// whatever newer runtime is present, so C# script steps don't additionally require the exact
+        /// runtime dotnet-script was built against.
+        /// </summary>
+        static Dictionary<string, string> WithDotnetRollForward(Dictionary<string, string>? environmentVars)
+        {
+            var vars = environmentVars == null
+                ? new Dictionary<string, string>()
+                : new Dictionary<string, string>(environmentVars);
+
+            // Don't override an explicit value - the surrounding environment may have set one deliberately.
+            if (!vars.ContainsKey(DotnetRollForwardVariableName))
+                vars[DotnetRollForwardVariableName] = "Major";
+
+            return vars;
+        }
+
         private string GetExecutable(string? localDotnetScriptPath, string bundledExecutable)
         {
             return string.IsNullOrWhiteSpace(localDotnetScriptPath)