diff --git a/ChangeLog b/ChangeLog
index f965d6f376..b5748d7e31 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2007-05-21  Wim Taymans  <wim@fluendo.com>
+
+	* libs/gst/base/gstbasetransform.h:
+	Fix macro for locking/unlocking the transform lock.
+
 2007-05-19  Tim-Philipp Müller  <tim at centricular dot net>
 
 	* docs/plugins/tmpl/.cvsignore:
diff --git a/libs/gst/base/gstbasetransform.h b/libs/gst/base/gstbasetransform.h
index 3f042e8217..dd0501d804 100644
--- a/libs/gst/base/gstbasetransform.h
+++ b/libs/gst/base/gstbasetransform.h
@@ -85,7 +85,7 @@ G_BEGIN_DECLS
  *
  * Since: 0.10.13
  */
-#define GST_BASE_TRANSFORM_LOCK(obj)   g_mutex_lock (obj->transform_lock)
+#define GST_BASE_TRANSFORM_LOCK(obj)   g_mutex_lock (GST_BASE_TRANSFORM_CAST (obj)->transform_lock)
 
 /**
  * GST_BASE_TRANSFORM_UNLOCK:
@@ -95,7 +95,7 @@ G_BEGIN_DECLS
  *
  * Since: 0.10.13
  */
-#define GST_BASE_TRANSFORM_UNLOCK(obj) g_mutex_unlock (obj->transform_lock)
+#define GST_BASE_TRANSFORM_UNLOCK(obj) g_mutex_unlock (GST_BASE_TRANSFORM_CAST (obj)->transform_lock)
 
 typedef struct _GstBaseTransform GstBaseTransform;
 typedef struct _GstBaseTransformClass GstBaseTransformClass;