diff --git a/opppy/interactive_utils.py b/opppy/interactive_utils.py
index b253e6b..005faba 100644
--- a/opppy/interactive_utils.py
+++ b/opppy/interactive_utils.py
@@ -250,6 +250,7 @@ def get_interactive_plot_parser(self):
       parser.add_argument('-p','--plot', dest='plot', help='re-open plot', nargs='?', type=bool, const=True, default=False)
       parser.add_argument('-l','--labels', dest='legend_labels', help='specify the legend labels [line1_label, line2_label,...]', type=str, nargs='+')
       parser.add_argument('-rs','--resize', dest='plot_size', help='specify the plot size [x_size, y_size]', type=float, nargs=2)
+      parser.add_argument('-nt','--nthreads', dest='nthreads', help='Number of threads to use during parsing', nargs='?', type=int, default=0)
     
       add_plot_options(parser)
       return parser
diff --git a/opppy/output.py b/opppy/output.py
index b90751c..8e19814 100644
--- a/opppy/output.py
+++ b/opppy/output.py
@@ -395,7 +395,7 @@ def thread_all(file_name, file_index, result_l):
     print('')
     print_dictionary_data(data)
 
-def build_output_dictionary_list(file_lists, opppy_parser):
+def build_output_dictionary_list(file_lists, opppy_parser, nthreads):
     '''
     append_pickle - 
       This function generates a opppy output dictionary
@@ -412,7 +412,7 @@ def build_output_dictionary_list(file_lists, opppy_parser):
         # build a new dictionary
         data = {}
         data['version'] = __version__
-        append_output_dictionary(data, output_files, opppy_parser)
+        append_output_dictionary(data, output_files, opppy_parser, nthreads=nthreads)
         dictionary_data.append(data)
     
     
diff --git a/opppy/tally.py b/opppy/tally.py
index 8a2b2d6..e2f0c0c 100644
--- a/opppy/tally.py
+++ b/opppy/tally.py
@@ -295,7 +295,7 @@ def thread_all(file_name, file_index, result_l):
     print('')
     print_tally_data(data)
 
-def build_tally_dictionary_list(file_lists, opppy_parser):
+def build_tally_dictionary_list(file_lists, opppy_parser, nthreads):
     '''
     append_pickle - 
       This function generates a opppy output dictionary
@@ -312,7 +312,7 @@ def build_tally_dictionary_list(file_lists, opppy_parser):
         # build a new dictionary
         data = {}
         data['version'] = __version__
-        append_tally_dictionary(data, output_files, opppy_parser)
+        append_tally_dictionary(data, output_files, opppy_parser, nthreads=nthreads)
         dictionary_data.append(data)