diff --git a/Scripts/generate-xcodeproj.sh b/Scripts/generate-xcodeproj.sh
index 6806720..289d9c1 100755
--- a/Scripts/generate-xcodeproj.sh
+++ b/Scripts/generate-xcodeproj.sh
@@ -6,5 +6,19 @@ set -euo pipefail
 ROOT="$(cd "$(dirname "$0")/.." && pwd)"
 cd "$ROOT"
 
+# XcodeGen requires configFiles listed in project.yml to exist on disk.
+# Signing.local.xcconfig is gitignored so each machine keeps its own team ID.
+SIGNING_LOCAL="$ROOT/Signing.local.xcconfig"
+SIGNING_EXAMPLE="$ROOT/Signing.local.xcconfig.example"
+if [[ ! -f "$SIGNING_LOCAL" ]]; then
+  if [[ ! -f "$SIGNING_EXAMPLE" ]]; then
+    echo "error: missing $SIGNING_EXAMPLE" >&2
+    exit 1
+  fi
+  cp "$SIGNING_EXAMPLE" "$SIGNING_LOCAL"
+  echo "Created $SIGNING_LOCAL from Signing.local.xcconfig.example"
+  echo "Edit DEVELOPMENT_TEAM there if you use a personal Apple Developer account."
+fi
+
 xcodegen generate
 "$ROOT/Scripts/patch-icon-composer.sh"
diff --git a/Signing.local.xcconfig.example b/Signing.local.xcconfig.example
new file mode 100644
index 0000000..336d4a9
--- /dev/null
+++ b/Signing.local.xcconfig.example
@@ -0,0 +1,10 @@
+// Signing.local.xcconfig.example
+// Copy to Signing.local.xcconfig (gitignored) for local signing overrides.
+// `./Scripts/generate-xcodeproj.sh` creates Signing.local.xcconfig from this
+// file automatically when it is missing.
+//
+// Replace DEVELOPMENT_TEAM with your Apple Developer Team ID if you are not
+// building with the project's default team.
+
+DEVELOPMENT_TEAM = X329MZU23S
+CODE_SIGN_STYLE = Automatic