diff --git a/src/pyrmv/raw/board_arrival.py b/src/pyrmv/raw/board_arrival.py
index 1e34527..b6674ec 100644
--- a/src/pyrmv/raw/board_arrival.py
+++ b/src/pyrmv/raw/board_arrival.py
@@ -64,7 +64,7 @@ def board_arrival(
     payload = {}
     headers = {"Accept": "application/json"} if json else {"Accept": "application/xml"}
 
-    for var, val in locals().items():
+    for var, val in locals().copy().items():
         if str(var) == "date":
             if val != None:
                 if isinstance(val, datetime):
diff --git a/src/pyrmv/raw/board_departure.py b/src/pyrmv/raw/board_departure.py
index e3cef29..dafe1fc 100644
--- a/src/pyrmv/raw/board_departure.py
+++ b/src/pyrmv/raw/board_departure.py
@@ -65,7 +65,7 @@ def board_departure(
     payload = {}
     headers = {"Accept": "application/json"} if json else {"Accept": "application/xml"}
 
-    for var, val in locals().items():
+    for var, val in locals().copy().items():
         if str(var) == "date":
             if val != None:
                 if isinstance(val, datetime):
diff --git a/src/pyrmv/raw/him_search.py b/src/pyrmv/raw/him_search.py
index bd6a2c3..535a8e6 100644
--- a/src/pyrmv/raw/him_search.py
+++ b/src/pyrmv/raw/him_search.py
@@ -97,7 +97,7 @@ def him_search(
     payload = {}
     headers = {"Accept": "application/json"} if json else {"Accept": "application/xml"}
 
-    for var, val in locals().items():
+    for var, val in locals().copy().items():
         if str(var) in {"dateB", "dateE"}:
             if val != None:
                 if isinstance(val, datetime):
diff --git a/src/pyrmv/raw/journey_detail.py b/src/pyrmv/raw/journey_detail.py
index 81235c2..39236d8 100644
--- a/src/pyrmv/raw/journey_detail.py
+++ b/src/pyrmv/raw/journey_detail.py
@@ -55,7 +55,7 @@ def journey_detail(
     payload = {}
     headers = {"Accept": "application/json"} if json else {"Accept": "application/xml"}
 
-    for var, val in locals().items():
+    for var, val in locals().copy().items():
         if str(var) == "rtMode":
             if val != None:
                 payload["rtMode"] = val.upper()
diff --git a/src/pyrmv/raw/stop_by_coords.py b/src/pyrmv/raw/stop_by_coords.py
index b8c7f05..b4fbdf4 100644
--- a/src/pyrmv/raw/stop_by_coords.py
+++ b/src/pyrmv/raw/stop_by_coords.py
@@ -54,7 +54,7 @@ def stop_by_coords(
     payload = {}
     headers = {"Accept": "application/json"} if json else {"Accept": "application/xml"}
 
-    for var, val in locals().items():
+    for var, val in locals().copy().items():
         if str(var) == "stopType":
             if val != None:
                 payload["type"] = val.upper()
diff --git a/src/pyrmv/raw/stop_by_name.py b/src/pyrmv/raw/stop_by_name.py
index 5355a0b..5ac372c 100644
--- a/src/pyrmv/raw/stop_by_name.py
+++ b/src/pyrmv/raw/stop_by_name.py
@@ -65,7 +65,7 @@ def stop_by_name(
     payload = {}
     headers = {"Accept": "application/json"} if json else {"Accept": "application/xml"}
 
-    for var, val in locals().items():
+    for var, val in locals().copy().items():
         if str(var) == "inputString":
             if val != None:
                 payload["input"] = val
diff --git a/src/pyrmv/raw/trip_find.py b/src/pyrmv/raw/trip_find.py
index 8465074..887b2cd 100644
--- a/src/pyrmv/raw/trip_find.py
+++ b/src/pyrmv/raw/trip_find.py
@@ -201,7 +201,7 @@ def trip_find(
     payload = {}
     headers = {"Accept": "application/json"} if json else {"Accept": "application/xml"}
 
-    for var, val in locals().items():
+    for var, val in locals().copy().items():
         if str(var) == "date":
             if val != None:
                 if isinstance(val, datetime):
diff --git a/src/pyrmv/raw/trip_recon.py b/src/pyrmv/raw/trip_recon.py
index e916e1e..ccb0941 100644
--- a/src/pyrmv/raw/trip_recon.py
+++ b/src/pyrmv/raw/trip_recon.py
@@ -87,7 +87,7 @@ def trip_recon(
     payload = {}
     headers = {"Accept": "application/json"} if json else {"Accept": "application/xml"}
 
-    for var, val in locals().items():
+    for var, val in locals().copy().items():
         if str(var) == "date":
             if val != None:
                 if isinstance(val, datetime):