diff --git a/fuzzers/074-dump_all/reduce_tile_types.py b/fuzzers/074-dump_all/reduce_tile_types.py
index 84de0f04..a12b3ef5 100644
--- a/fuzzers/074-dump_all/reduce_tile_types.py
+++ b/fuzzers/074-dump_all/reduce_tile_types.py
@@ -283,6 +283,8 @@ def annotate_pips_speed_model(pips, speed_data):
             'res': pip_speed_data.get('reverse_res', None),
         }
 
+        del pips[pip_name]['speed_model_index']
+
 
 def annotate_site_pins_speed_model(site_pins, speed_data):
     """ Updates the site_pins with correct timing data """
@@ -306,6 +308,8 @@ def annotate_site_pins_speed_model(site_pins, speed_data):
         if res != 'null':
             site_pins[site_pin_name]['res'] = res
 
+        del site_pins[site_pin_name]['speed_model_index']
+
 
 def annotate_wires_speed_model(wires, speed_data):
     """ Updates the wires with correct timing data """