diff --git a/src/ocrmypdf/optimize.py b/src/ocrmypdf/optimize.py
index 69e1e844..08958e61 100644
--- a/src/ocrmypdf/optimize.py
+++ b/src/ocrmypdf/optimize.py
@@ -681,9 +681,9 @@ def optimize(
         safe_symlink(input_file, output_file)
         return output_file
 
-    if options.jpg_quality == 0:
+    if not options.jpg_quality:
         options.jpg_quality = DEFAULT_JPEG_QUALITY if options.optimize < 3 else 40
-    if options.png_quality == 0:
+    if not options.png_quality:
         options.png_quality = DEFAULT_PNG_QUALITY if options.optimize < 3 else 30
 
     with Pdf.open(input_file) as pdf: