diff --git a/pyclustering/nnet/fsync.py b/pyclustering/nnet/fsync.py
index 66107379..a80120bc 100755
--- a/pyclustering/nnet/fsync.py
+++ b/pyclustering/nnet/fsync.py
@@ -335,7 +335,7 @@ def __calculate_amplitude(self, amplitude, t, argv):
         
         """
         
-        z = amplitude.view(numpy.complex);
+        z = amplitude.view(numpy.complex128);
         dzdt = self.__landau_stuart(z, argv) + self.__synchronization_mechanism(z, argv);
         
         return dzdt.view(numpy.float64);
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