diff --git a/src/IKVM.Tools.Runner/Importer/IkvmImporterLauncher.cs b/src/IKVM.Tools.Runner/Importer/IkvmImporterLauncher.cs
index 34c657453..6308afb34 100644
--- a/src/IKVM.Tools.Runner/Importer/IkvmImporterLauncher.cs
+++ b/src/IKVM.Tools.Runner/Importer/IkvmImporterLauncher.cs
@@ -70,7 +70,7 @@ public async Task<int> ExecuteAsync(IkvmImporterOptions options, CancellationTok
                 w.WriteLine($"-out \"{options.Output}\"");
 
             if (options.Assembly is not null)
-                w.WriteLine($"-assembly {options.Assembly}");
+                w.WriteLine($"-assembly \"{options.Assembly}\"");
 
             if (options.Version is not null)
                 w.WriteLine($"-version {options.Version}");