diff --git a/Lib/imaplib.py b/Lib/imaplib.py
index 96fdf83..3dd7e07 100644
--- a/Lib/imaplib.py
+++ b/Lib/imaplib.py
@@ -1105,7 +1105,7 @@
         while read < size:
             data = self.sslobj.read(size-read)
             read += len(data)
-            chunks.append(size)
+            chunks.append(data)
 
         return ''.join(chunks)