diff --git a/packages/server/scripts/copy-opencode-config.mjs b/packages/server/scripts/copy-opencode-config.mjs
index ec725ae2..b04d276c 100644
--- a/packages/server/scripts/copy-opencode-config.mjs
+++ b/packages/server/scripts/copy-opencode-config.mjs
@@ -23,6 +23,8 @@ if (!existsSync(nodeModulesDir)) {
 
   const npmArgs = [
     "install",
+    "--prefix",
+    sourceDir,
     "--omit=dev",
     "--ignore-scripts",
     "--fund=false",