diff --git a/ext/wavpack/gstwavpackdec.h b/ext/wavpack/gstwavpackdec.h
index 1f4a383523..0d8459e70b 100644
--- a/ext/wavpack/gstwavpackdec.h
+++ b/ext/wavpack/gstwavpackdec.h
@@ -34,10 +34,10 @@ G_BEGIN_DECLS
 #define GST_WAVPACK_DEC(obj) \
   (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_WAVPACK_DEC,GstWavpackDec))
 #define GST_WAVPACK_DEC_CLASS(klass) \
-  (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_WAVPACK_DEC,GstWavpackDec))
+  (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_WAVPACK_DEC,GstWavpackDecClass))
 #define GST_IS_WAVPACK_DEC(obj) \
   (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_WAVPACK_DEC))
-#define GST_IS_WAVPACK_DEC_CLASS(obj) \
+#define GST_IS_WAVPACK_DEC_CLASS(klass) \
   (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_WAVPACK_DEC))
 
 typedef struct _GstWavpackDec      GstWavpackDec;
diff --git a/ext/wavpack/gstwavpackparse.h b/ext/wavpack/gstwavpackparse.h
index 99f3a89a4b..9e6c334d19 100644
--- a/ext/wavpack/gstwavpackparse.h
+++ b/ext/wavpack/gstwavpackparse.h
@@ -32,10 +32,10 @@ G_BEGIN_DECLS
 #define GST_WAVPACK_PARSE(obj) \
   (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_WAVPACK_PARSE,GstWavpackParse))
 #define GST_WAVPACK_PARSE_CLASS(klass) \
-  (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_WAVPACK_PARSE,GstWavpackParse))
+  (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_WAVPACK_PARSE,GstWavpackParseClass))
 #define GST_IS_WAVPACK_PARSE(obj) \
   (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_WAVPACK_PARSE))
-#define GST_IS_WAVPACK_PARSE_CLASS(obj) \
+#define GST_IS_WAVPACK_PARSE_CLASS(klass) \
   (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_WAVPACK_PARSE))
 
 typedef struct _GstWavpackParse           GstWavpackParse;
diff --git a/gst/qtdemux/qtdemux.h b/gst/qtdemux/qtdemux.h
index 3a5d5c774b..37cfad8eeb 100644
--- a/gst/qtdemux/qtdemux.h
+++ b/gst/qtdemux/qtdemux.h
@@ -31,10 +31,10 @@ G_BEGIN_DECLS
 #define GST_QTDEMUX(obj) \
   (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_QTDEMUX,GstQTDemux))
 #define GST_QTDEMUX_CLASS(klass) \
-  (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_QTDEMUX,GstQTDemux))
+  (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_QTDEMUX,GstQTDemuxClass))
 #define GST_IS_QTDEMUX(obj) \
   (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_QTDEMUX))
-#define GST_IS_QTDEMUX_CLASS(obj) \
+#define GST_IS_QTDEMUX_CLASS(klass) \
   (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_QTDEMUX))
 
 #define GST_QTDEMUX_MAX_STREAMS         8
diff --git a/gst/spectrum/gstspectrum.h b/gst/spectrum/gstspectrum.h
index 8e536786f7..a6c918c04a 100644
--- a/gst/spectrum/gstspectrum.h
+++ b/gst/spectrum/gstspectrum.h
@@ -33,7 +33,7 @@ extern "C" {
 #define GST_TYPE_SPECTRUM            (gst_spectrum_get_type())
 #define GST_SPECTRUM(obj)            (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_SPECTRUM,GstSpectrum))
 #define GST_IS_SPECTRUM(obj)         (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_SPECTRUM))
-#define GST_SPECTRUM_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST((klass), GST_TYPE_SPECTRUM,GstSpectrum))
+#define GST_SPECTRUM_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST((klass), GST_TYPE_SPECTRUM,GstSpectrumClass))
 #define GST_IS_SPECTRUM_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), GST_TYPE_SPECTRUM))
 
 typedef struct _GstSpectrum GstSpectrum;
diff --git a/sys/directdraw/gstdirectdrawsink.h b/sys/directdraw/gstdirectdrawsink.h
index c144f64691..39d879eb7f 100644
--- a/sys/directdraw/gstdirectdrawsink.h
+++ b/sys/directdraw/gstdirectdrawsink.h
@@ -32,11 +32,11 @@
 #include <ddraw.h>
 
 G_BEGIN_DECLS
-#define GST_TYPE_DIRECTDRAW_SINK          (gst_directdrawsink_get_type())
-#define GST_DIRECTDRAW_SINK(obj)          (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_DIRECTDRAW_SINK,GstDirectDrawSink))
-#define GST_DIRECTDRAW_SINK_CLASS(klass)  (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_DIRECTDRAW_SINK,GstDirectDrawSinkClass))
-#define GST_IS_DIRECTDRAW_SINK(obj)       (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_DIRECTDRAW_SINK))
-#define GST_IS_DIRECTDRAW_SINK_CLASS(obj) (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_DIRECTDRAW_SINK))
+#define GST_TYPE_DIRECTDRAW_SINK            (gst_directdrawsink_get_type())
+#define GST_DIRECTDRAW_SINK(obj)            (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_DIRECTDRAW_SINK,GstDirectDrawSink))
+#define GST_DIRECTDRAW_SINK_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_DIRECTDRAW_SINK,GstDirectDrawSinkClass))
+#define GST_IS_DIRECTDRAW_SINK(obj)         (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_DIRECTDRAW_SINK))
+#define GST_IS_DIRECTDRAW_SINK_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_DIRECTDRAW_SINK))
 typedef struct _GstDirectDrawSink GstDirectDrawSink;
 typedef struct _GstDirectDrawSinkClass GstDirectDrawSinkClass;
 
diff --git a/sys/directsound/gstdirectsoundsink.h b/sys/directsound/gstdirectsoundsink.h
index 54f7148e78..9f10764247 100644
--- a/sys/directsound/gstdirectsoundsink.h
+++ b/sys/directsound/gstdirectsoundsink.h
@@ -32,11 +32,11 @@
 
 
 G_BEGIN_DECLS
-#define GST_TYPE_DIRECTSOUND_SINK          (gst_directsoundsink_get_type())
-#define GST_DIRECTSOUND_SINK(obj)          (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_DIRECTSOUND_SINK,GstDirectSoundSink))
-#define GST_DIRECTSOUND_SINK_CLASS(klass)  (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_DIRECTSOUND_SINK,GstDirectSoundSinkClass))
-#define GST_IS_DIRECTSOUND_SINK(obj)       (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_DIRECTSOUND_SINK))
-#define GST_IS_DIRECTSOUND_SINK_CLASS(obj) (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_DIRECTSOUND_SINK))
+#define GST_TYPE_DIRECTSOUND_SINK            (gst_directsoundsink_get_type())
+#define GST_DIRECTSOUND_SINK(obj)            (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_DIRECTSOUND_SINK,GstDirectSoundSink))
+#define GST_DIRECTSOUND_SINK_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_DIRECTSOUND_SINK,GstDirectSoundSinkClass))
+#define GST_IS_DIRECTSOUND_SINK(obj)         (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_DIRECTSOUND_SINK))
+#define GST_IS_DIRECTSOUND_SINK_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_DIRECTSOUND_SINK))
 typedef struct _GstDirectSoundSink GstDirectSoundSink;
 typedef struct _GstDirectSoundSinkClass GstDirectSoundSinkClass;