diff --git a/ChangeLog b/ChangeLog
index 13047d535..815804464 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2015-09-08 Niels Grewe <niels.grewe@halbordnung.de>
+
+	* Source/NSPropertyList.m: Fix writing base64 data.
+
 2015-09-04 Niels Grewe <niels.grewe@halbordnung.de>
 
 	* Source/GSString.m: Optimisation for formatting strings that are stored as
diff --git a/Source/NSPropertyList.m b/Source/NSPropertyList.m
index c5d0d8594..798821dcd 100644
--- a/Source/NSPropertyList.m
+++ b/Source/NSPropertyList.m
@@ -1487,7 +1487,7 @@ encodeBase64(NSData *source, NSMutableData *dest)
 
       [dest setLength: base + destlen];
       GSPrivateEncodeBase64((const uint8_t*)[source bytes],
-        length, (uint8_t*)[dest mutableBytes]);
+        length, (uint8_t*)[dest mutableBytes] + base);
     }
 }