diff --git a/examples/run_og_zaf.py b/examples/run_og_zaf.py
index 14eae4d..a4c8a6f 100644
--- a/examples/run_og_zaf.py
+++ b/examples/run_og_zaf.py
@@ -14,6 +14,7 @@
 from ogcore import output_plots as op
 from ogcore.execute import runner
 from ogcore.utils import safe_read_pickle
+from ogzaf.utils import is_connected
 
 # Use a custom matplotlib style file for plots
 plt.style.use("ogcore.OGcorePlots")
@@ -50,9 +51,10 @@ def main():
         defaults = json.load(file)
     p.update_specifications(defaults)
     # Update parameters from calibrate.py Calibration class
-    c = Calibration(p)
-    updated_params = c.get_dict()
-    p.update_specifications(updated_params)
+    if is_connected():  # only update if connected to internet
+        c = Calibration(p)
+        updated_params = c.get_dict()
+        p.update_specifications(updated_params)
 
     # Run model
     start_time = time.time()
diff --git a/ogzaf/input_output.py b/ogzaf/input_output.py
index e6d2bee..6db9288 100644
--- a/ogzaf/input_output.py
+++ b/ogzaf/input_output.py
@@ -1,5 +1,6 @@
 import pandas as pd
 import numpy as np
+from ogzaf.utils import is_connected
 from ogzaf.constants import CONS_DICT, PROD_DICT
 
 """
@@ -8,13 +9,16 @@
 # Read in SAM file
 storage_options = {"User-Agent": "Mozilla/5.0"}
 SAM_path = "https://www.wider.unu.edu/sites/default/files/Data/SASAM-2015-Data-Resource.xlsx"
-SAM = pd.read_excel(
-    SAM_path,
-    sheet_name="Micro SAM 2015",
-    skiprows=6,
-    index_col=0,
-    storage_options=storage_options,
-)
+if is_connected():
+    SAM = pd.read_excel(
+        SAM_path,
+        sheet_name="Micro SAM 2015",
+        skiprows=6,
+        index_col=0,
+        storage_options=storage_options,
+    )
+else:
+    SAM = None
 
 
 def get_alpha_c(sam=SAM, cons_dict=CONS_DICT):