diff --git a/gait_analysis/function/utils.py b/gait_analysis/function/utils.py
index a693e89..1e2b162 100644
--- a/gait_analysis/function/utils.py
+++ b/gait_analysis/function/utils.py
@@ -516,7 +516,7 @@ def get_calibration(session_id,session_path):
 def download_and_switch_calibration(session_id,session_path,calibTrialID = None):
     if calibTrialID == None:
         calibTrialID = get_calibration_trial_id(session_id)
-    resp = requests.get("https://api.opencap.ai/trials/{}/".format(calibTrialID),
+    resp = requests.get("{}trials/{}/".format(API_URL, calibTrialID),
                          headers = {"Authorization": "Token {}".format(API_TOKEN)})
     trial = resp.json()
        
diff --git a/max_centerofmass_vpos/function/utils.py b/max_centerofmass_vpos/function/utils.py
index 7f62b7b..a1db3ab 100644
--- a/max_centerofmass_vpos/function/utils.py
+++ b/max_centerofmass_vpos/function/utils.py
@@ -472,7 +472,7 @@ def get_calibration(session_id,session_path):
 def download_and_switch_calibration(session_id,session_path,calibTrialID = None):
     if calibTrialID == None:
         calibTrialID = get_calibration_trial_id(session_id)
-    resp = requests.get("https://api.opencap.ai/trials/{}/".format(calibTrialID),
+    resp = requests.get("{}trials/{}/".format(API_URL, calibTrialID),
                          headers = {"Authorization": "Token {}".format(API_TOKEN)})
     trial = resp.json()
        
diff --git a/treadmill_gait_analysis/function/utils.py b/treadmill_gait_analysis/function/utils.py
index a693e89..1e2b162 100644
--- a/treadmill_gait_analysis/function/utils.py
+++ b/treadmill_gait_analysis/function/utils.py
@@ -516,7 +516,7 @@ def get_calibration(session_id,session_path):
 def download_and_switch_calibration(session_id,session_path,calibTrialID = None):
     if calibTrialID == None:
         calibTrialID = get_calibration_trial_id(session_id)
-    resp = requests.get("https://api.opencap.ai/trials/{}/".format(calibTrialID),
+    resp = requests.get("{}trials/{}/".format(API_URL, calibTrialID),
                          headers = {"Authorization": "Token {}".format(API_TOKEN)})
     trial = resp.json()