diff --git a/lib/scripts/legacy_lyxpreview2ppm.py b/lib/scripts/legacy_lyxpreview2ppm.py
index 86d9b17d89..58f02144b1 100644
--- a/lib/scripts/legacy_lyxpreview2ppm.py
+++ b/lib/scripts/legacy_lyxpreview2ppm.py
@@ -462,4 +462,4 @@ def legacy_conversion_step3(latex_file, dpi, output_format, dvips_failed, skipMe
 
 
 if __name__ == "__main__":
-    exit(legacy_conversion(sys.argv)[0])
+    sys.exit(legacy_conversion(sys.argv)[0])