diff --git a/pyzebra/app/panel_ccl_integrate.py b/pyzebra/app/panel_ccl_integrate.py
index d7f0e7a..3dac9e7 100644
--- a/pyzebra/app/panel_ccl_integrate.py
+++ b/pyzebra/app/panel_ccl_integrate.py
@@ -426,7 +426,7 @@ def create():
 
         if function == "linear":
             fitparams["value"] = [0, 0]
-            fitparams["vary"] = [False, False]
+            fitparams["vary"] = [False, True]
 
         return fitparams
 
diff --git a/pyzebra/app/panel_param_study.py b/pyzebra/app/panel_param_study.py
index 79966b0..ea174bf 100644
--- a/pyzebra/app/panel_param_study.py
+++ b/pyzebra/app/panel_param_study.py
@@ -520,7 +520,7 @@ def create():
 
         if function == "linear":
             fitparams["value"] = [0, 0]
-            fitparams["vary"] = [False, False]
+            fitparams["vary"] = [False, True]
 
         return fitparams