diff --git a/build.py b/build.py
index 7e63a6b..5e145c7 100644
--- a/build.py
+++ b/build.py
@@ -2,7 +2,8 @@ import os
 import subprocess
 
 if __name__ == "__main__":
-    if os.getenv('SKIP_BUILD_FRONTEND') is None:
+    # Building the frontend is optional
+    if os.getenv('SKIP_BUILD_FRONTEND') is None and os.path.exists('package.json'):
         # When building the backend, make sure the frontend is built first
         subprocess.run(['yarn', 'install'], check=True)
         subprocess.run(['yarn', 'build', '--outDir', 'yacv_server/frontend'], check=True)
diff --git a/pyproject.toml b/pyproject.toml
index 734556c..6ee06da 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "yacv-server"
-version = "0.4.1"  # TODO: Update automatically by CI on release (also for package.json!)
+version = "0.4.2"  # TODO: Update automatically by CI on release (also for package.json!)
 description = "Yet Another CAD Viewer (server)"
 authors = ["Yeicor <4929005+Yeicor@users.noreply.github.com>"]
 license = "MIT"