diff --git a/StabilityMatrix.Core/Processes/ProcessRunner.cs b/StabilityMatrix.Core/Processes/ProcessRunner.cs
index 5a9e5191..99edcf7e 100644
--- a/StabilityMatrix.Core/Processes/ProcessRunner.cs
+++ b/StabilityMatrix.Core/Processes/ProcessRunner.cs
@@ -125,7 +125,9 @@ public static class ProcessRunner
         Dictionary<string, string>? environmentVariables = null)
     {
         // Quote arguments containing spaces
-        var args = string.Join(" ", arguments.Select(Quote));
+        var args = string.Join(" ", arguments
+            .Where(s => !string.IsNullOrEmpty(s))
+            .Select(Quote));
         return StartProcess(fileName, args, workingDirectory, outputDataReceived, environmentVariables);
     }
     
diff --git a/StabilityMatrix.Core/Python/PyVenvRunner.cs b/StabilityMatrix.Core/Python/PyVenvRunner.cs
index 1297135e..c9dce51e 100644
--- a/StabilityMatrix.Core/Python/PyVenvRunner.cs
+++ b/StabilityMatrix.Core/Python/PyVenvRunner.cs
@@ -93,8 +93,9 @@ public class PyVenvRunner : IDisposable
         // Create RootPath if it doesn't exist
         RootPath.Create();
 
-        // Create venv
-        var args = new string[] { "-m", "virtualenv", "--always-copy", RootPath };
+        // Create venv (copy mode if windows)
+        var args = new string[] { "-m", "virtualenv", 
+            Compat.IsWindows ? "--always-copy" : "", RootPath };
         var venvProc = ProcessRunner.StartProcess(PyRunner.PythonExePath, args);
         await venvProc.WaitForExitAsync();