diff --git a/xmlescpos/escpos.py b/xmlescpos/escpos.py
index ed9e57c..1e90c0f 100644
--- a/xmlescpos/escpos.py
+++ b/xmlescpos/escpos.py
@@ -445,7 +445,7 @@ def print_base64_image(self,img):
             img_rgba = Image.open(f)
             img = Image.new('RGB', img_rgba.size, (255,255,255))
             channels = img_rgba.split()
-            if len(channels) > 1:
+            if len(channels) > 3:
                 # use alpha channel as mask
                 img.paste(img_rgba, mask=channels[3])
             else: