diff --git a/ChangeLog b/ChangeLog
index af2b7f1c91..9463534739 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2008-05-13  Sebastian Dröge  <slomo@circular-chaos.org>
+
+	Patch by: Sjoerd Simons <sjoerd at luon dot net>
+
+	* libs/gst/base/gstbasetransform.c:
+	(gst_base_transform_buffer_alloc):
+	Check the caps of the buffer returned by gst_pad_alloc_buffer() and
+	fall back to default negotiation in the chain function if the caps
+	are different from what was requested. Fixes bug #526768.
+
 2008-05-09  Tim-Philipp Müller  <tim.muller at collabora co uk>
 
 	* gst/gstsegment.c:
diff --git a/common b/common
index dbf8f3aece..2d9c09df0f 160000
--- a/common
+++ b/common
@@ -1 +1 @@
-Subproject commit dbf8f3aeceb6e57de097951a670cd853b4886ad8
+Subproject commit 2d9c09df0fe4ad3f570fea9f649cfc6c4511080d
diff --git a/libs/gst/base/gstbasetransform.c b/libs/gst/base/gstbasetransform.c
index c1c7b604d4..a477f13dbc 100644
--- a/libs/gst/base/gstbasetransform.c
+++ b/libs/gst/base/gstbasetransform.c
@@ -1214,6 +1214,13 @@ not_configured:
         && gst_pad_peer_accept_caps (trans->srcpad, caps)) {
       /* ...by seeing if the downstream elements can handle this */
       res = gst_pad_alloc_buffer (trans->srcpad, offset, size, caps, buf);
+
+      if (res == GST_FLOW_OK
+          && !gst_caps_is_equal (caps, GST_BUFFER_CAPS (*buf))) {
+        /* In case downstream wants to see something different, ignore this
+         * buffer and leave it to the chain function to renegotiate */
+        gst_buffer_replace (buf, NULL);
+      }
     } else {
       /* If not fall back on the default handler and let things be
        * renegotiated in the chain function */