diff --git a/gst/moodbar/gstfftwspectrum.c b/gst/moodbar/gstfftwspectrum.c
index 8b32e93b8..7f502802c 100644
--- a/gst/moodbar/gstfftwspectrum.c
+++ b/gst/moodbar/gstfftwspectrum.c
@@ -221,6 +221,8 @@ gst_fftwspectrum_init (GstFFTWSpectrum * conv,
   conv->def_size = DEF_SIZE_DEFAULT;
   conv->def_step = DEF_STEP_DEFAULT;
   conv->hi_q     = HIQUALITY_DEFAULT;
+
+  g_mutex_init(&conv->mutex);
 }
 
 static void
@@ -303,13 +305,12 @@ alloc_fftw_data (GstFFTWSpectrum *conv)
    * implementing filters.
    */
 
-  static GStaticMutex mutex = G_STATIC_MUTEX_INIT;
-  g_static_mutex_lock(&mutex);
+  g_mutex_lock(&conv->mutex);
   conv->fftw_plan 
     = fftw_plan_dft_r2c_1d(conv->size, conv->fftw_in,
           (fftw_complex *) conv->fftw_out,
 			    conv->hi_q ? FFTW_MEASURE : FFTW_ESTIMATE);
-  g_static_mutex_unlock(&mutex);
+  g_mutex_unlock(&conv->mutex);
 }
 
 
diff --git a/gst/moodbar/gstfftwspectrum.h b/gst/moodbar/gstfftwspectrum.h
index fc7647e7c..fe9a2f0e2 100644
--- a/gst/moodbar/gstfftwspectrum.h
+++ b/gst/moodbar/gstfftwspectrum.h
@@ -54,6 +54,8 @@ struct _GstFFTWSpectrum
   /* Properties */
   gint32   def_size, def_step;
   gboolean hi_q;
+
+  GMutex mutex;
 };
 
 struct _GstFFTWSpectrumClass