diff --git a/sorl/thumbnail/engines/pil_engine.py b/sorl/thumbnail/engines/pil_engine.py
index 5371be42c..e67572976 100644
--- a/sorl/thumbnail/engines/pil_engine.py
+++ b/sorl/thumbnail/engines/pil_engine.py
@@ -151,6 +151,8 @@ def _colorspace(self, image, colorspace, format):
             # Pillow JPEG doesn't allow RGBA anymore. It was converted to RGB before.
             if image.mode == 'RGBA' and format != 'JPEG':
                 return image  # RGBA is just RGB + Alpha
+            if image.mode == 'RGBA' and format == 'JPEG' and image.format != 'JPEG':
+                return image.convert('RGB')
             if image.mode == 'LA' or (
                 image.mode == 'P' and 'transparency' in image.info and format != 'JPEG'
             ):