diff --git a/tvb_contrib/tvb/contrib/cosimulation/cosimulator.py b/tvb_contrib/tvb/contrib/cosimulation/cosimulator.py
index 6e66893474..db106a51d0 100644
--- a/tvb_contrib/tvb/contrib/cosimulation/cosimulator.py
+++ b/tvb_contrib/tvb/contrib/cosimulation/cosimulator.py
@@ -151,7 +151,7 @@ def _configure_cosimulation(self):
 
         # Reconfigure the connectivity for regions modelled by the other cosimulator exclusively:
         if self.exclusive:
-            self.connectivity.weights[np.ix_(self.proxy_inds, self.proxy_inds)] = 0.0
+            self.connectivity.weights[numpy.ix_(self.proxy_inds, self.proxy_inds)] = 0.0
             self.connectivity.configure()
 
         # Configure the cosimulator monitor