diff --git a/epanet/epanet2.py b/epanet/epanet2.py
index ed0f151..bc297c0 100644
--- a/epanet/epanet2.py
+++ b/epanet/epanet2.py
@@ -254,7 +254,10 @@ def run_project(name: str, version: str = '3') -> str:
         data['simulation_result'] = 'failed'
     else:
         data['simulation_result'] = 'successful'
-        data |= _dump_output(opt)
+        if version == '2':
+            data |= _dump_output(opt)
+        else:
+            pass # TODO: epanet3 output format?
 
     data['report'] = dump_report(rpt)