diff --git a/src/ClaudeDo.Installer/ClaudeDo.Installer.csproj b/src/ClaudeDo.Installer/ClaudeDo.Installer.csproj
index 5aa49db..e6be71e 100644
--- a/src/ClaudeDo.Installer/ClaudeDo.Installer.csproj
+++ b/src/ClaudeDo.Installer/ClaudeDo.Installer.csproj
@@ -26,7 +26,10 @@
     <PublishTrimmed>false</PublishTrimmed>
     <IncludeNativeLibrariesForSelfExtract>true</IncludeNativeLibrariesForSelfExtract>
     <IncludeAllContentForSelfExtract>true</IncludeAllContentForSelfExtract>
-    <EnableCompressionInSingleFile>true</EnableCompressionInSingleFile>
+    <!-- Compression disabled: WPF + single-file + compression triggers AV in the
+         bundle extractor (0xc0000005 / COR_E_EXECUTIONENGINE) on some machines.
+         Trade ~30% exe size for reliable startup. -->
+    <EnableCompressionInSingleFile>false</EnableCompressionInSingleFile>
   </PropertyGroup>
 
   <ItemGroup>