diff --git a/PIL/PngImagePlugin.py b/PIL/PngImagePlugin.py
index dd54707d8..2e2600166 100644
--- a/PIL/PngImagePlugin.py
+++ b/PIL/PngImagePlugin.py
@@ -731,7 +731,9 @@ def _save(im, fp, filename, chunk=putchunk):
         name = b"ICC Profile"
         data = name + b"\0\0" + zlib.compress(icc)
         chunk(fp, b"iCCP", data)
-    else:
+        
+        # You must either have sRGB or iCCP.
+        # Disallow sRGB chunks when a iCCP-chunk has been emitted.
         chunks.remove(b"sRGB")
 
     info = im.encoderinfo.get("pnginfo")