diff --git a/api/inp_in.py b/api/inp_in.py
index 9080617..e43cc04 100644
--- a/api/inp_in.py
+++ b/api/inp_in.py
@@ -246,7 +246,7 @@ def parse_file(project: str, inp: str) -> None:
     print(f"Total (in second): {(end-start).seconds}(s)")
 
 
-def read_inp(project: str, inp: str) -> bool:
+def read_inp(project: str, inp: str, version: str = '3') -> bool:
     if is_project_open(project):
        close_project(project)
 
@@ -267,7 +267,7 @@ def read_inp(project: str, inp: str) -> bool:
     return True
 
 
-def import_inp(project: str, cs: ChangeSet) -> bool:
+def import_inp(project: str, cs: ChangeSet, version: str = '3') -> bool:
     if 'inp' not in cs.operations[0]:
         return False
 
diff --git a/api/inp_out.py b/api/inp_out.py
index 015556b..d6a5774 100644
--- a/api/inp_out.py
+++ b/api/inp_out.py
@@ -32,7 +32,7 @@ from .s27_backdrop import inp_out_backdrop
 #from .s28_end import *
 
 
-def dump_inp(project: str, inp: str):
+def dump_inp(project: str, inp: str, version: str = '3'):
     if not have_project(project):
        return
 
@@ -144,7 +144,7 @@ def dump_inp(project: str, inp: str):
     close_project(project)
 
 
-def export_inp(project: str) -> ChangeSet:
+def export_inp(project: str, version: str = '3') -> ChangeSet:
     if not have_project(project):
        return ChangeSet()
 
diff --git a/tjnetwork.py b/tjnetwork.py
index ade223f..75ddf32 100644
--- a/tjnetwork.py
+++ b/tjnetwork.py
@@ -185,17 +185,17 @@ def close_project(name: str) -> None:
 def copy_project(source: str, new: str) -> None:
     return api.copy_project(source, new)
 
-def read_inp(name: str, inp: str) -> bool:
-    return api.read_inp(name, inp)
+def read_inp(name: str, inp: str, version: str = '3') -> bool:
+    return api.read_inp(name, inp, version)
 
-def dump_inp(name: str, inp: str) -> None:
-    return api.dump_inp(name, inp)
+def dump_inp(name: str, inp: str, version: str = '3') -> None:
+    return api.dump_inp(name, inp, version)
 
-def import_inp(name: str, cs: ChangeSet) -> bool:
-    return api.import_inp(name, cs)
+def import_inp(name: str, cs: ChangeSet, version: str = '3') -> bool:
+    return api.import_inp(name, cs, version)
 
-def export_inp(name: str) -> ChangeSet:
-    return api.export_inp(name)
+def export_inp(name: str, version: str = '3') -> ChangeSet:
+    return api.export_inp(name, version)
 
 def run_project(name: str) -> str:
     return epanet.run_project(name)