diff --git a/ChangeLog b/ChangeLog
index 6cf0f8c51e..af61cf6ce0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2006-03-23  Tim-Philipp Müller  <tim at centricular dot net>
+
+	* ext/libpng/gstpngdec.c: (gst_pngdec_change_state):
+	  Make state change function thread-safe.
+
 2006-03-23  Tim-Philipp Müller  <tim at centricular dot net>
 
 	* gst/wavparse/gstwavparse.c: (gst_wavparse_get_upstream_size),
diff --git a/ext/libpng/gstpngdec.c b/ext/libpng/gstpngdec.c
index 684232888c..9bf672ce60 100644
--- a/ext/libpng/gstpngdec.c
+++ b/ext/libpng/gstpngdec.c
@@ -592,8 +592,8 @@ beach:
 static GstStateChangeReturn
 gst_pngdec_change_state (GstElement * element, GstStateChange transition)
 {
-  GstStateChangeReturn ret = GST_STATE_CHANGE_FAILURE;
-  GstPngDec *pngdec = NULL;
+  GstStateChangeReturn ret;
+  GstPngDec *pngdec;
 
   pngdec = GST_PNGDEC (element);
 
@@ -601,6 +601,15 @@ gst_pngdec_change_state (GstElement * element, GstStateChange transition)
     case GST_STATE_CHANGE_READY_TO_PAUSED:
       gst_pngdec_libpng_init (pngdec);
       break;
+    default:
+      break;
+  }
+
+  ret = parent_class->change_state (element, transition);
+  if (ret != GST_STATE_CHANGE_SUCCESS)
+    return ret;
+
+  switch (transition) {
     case GST_STATE_CHANGE_PAUSED_TO_READY:
       gst_pngdec_libpng_clear (pngdec);
       break;
@@ -608,8 +617,6 @@ gst_pngdec_change_state (GstElement * element, GstStateChange transition)
       break;
   }
 
-  ret = parent_class->change_state (element, transition);
-
   return ret;
 }