diff --git a/simulations/airshower_beacon_simulation/bd_antenna_phase_deltas.py b/simulations/airshower_beacon_simulation/bd_antenna_phase_deltas.py
index 37bd41e..45a76de 100755
--- a/simulations/airshower_beacon_simulation/bd_antenna_phase_deltas.py
+++ b/simulations/airshower_beacon_simulation/bd_antenna_phase_deltas.py
@@ -76,6 +76,8 @@ if __name__ == "__main__":
         if fig_dir:
             fig.savefig(path.join(fig_dir, __file__ + f".matrix.original.pdf"))
 
+        plt.close(fig)
+
 
     # Modify the matrix to let each column represent multiple
     # measurements of the same baseline (j,0) phase difference
@@ -97,6 +99,8 @@ if __name__ == "__main__":
             if fig_dir:
                 fig.savefig(path.join(fig_dir, __file__ + f".matrix.first_row.pdf"))
 
+            plt.close(fig)
+
         sigma_phase_matrix = sigma_phase_matrix - first_row
         sigma_phase_matrix = lib.phase_mod(sigma_phase_matrix)
 
@@ -130,6 +134,8 @@ if __name__ == "__main__":
         if fig_dir:
             fig.savefig(path.join(fig_dir, __file__ + f".matrix.modified.pdf"))
 
+        plt.close(fig)
+
     # write into antenna hdf5
     with h5py.File(antennas_fname, 'a') as fp:
         group = fp['antennas']