diff --git a/django/contrib/admin/options.py b/django/contrib/admin/options.py
index 0281fa84d6..019bfe9789 100644
--- a/django/contrib/admin/options.py
+++ b/django/contrib/admin/options.py
@@ -266,7 +266,7 @@ class ModelAdmin(BaseModelAdmin):
         if self.exclude is None:
             exclude = []
         else:
-            exclude = self.exclude
+            exclude = list(self.exclude)
         defaults = {
             "form": self.form,
             "fields": fields,
@@ -780,7 +780,7 @@ class InlineModelAdmin(BaseModelAdmin):
         if self.exclude is None:
             exclude = []
         else:
-            exclude = self.exclude
+            exclude = list(self.exclude)
         defaults = {
             "form": self.form,
             "formset": self.formset,
diff --git a/django/forms/models.py b/django/forms/models.py
index 6024a1c6c8..dad3483455 100644
--- a/django/forms/models.py
+++ b/django/forms/models.py
@@ -528,6 +528,7 @@ def inlineformset_factory(parent_model, model, form=ModelForm,
     if fk.unique:
         max_num = 1
     if exclude is not None:
+        exclude = list(exclude)
         exclude.append(fk.name)
     else:
         exclude = [fk.name]
diff --git a/tests/regressiontests/inline_formsets/models.py b/tests/regressiontests/inline_formsets/models.py
index c00703852f..8b6f5dd342 100644
--- a/tests/regressiontests/inline_formsets/models.py
+++ b/tests/regressiontests/inline_formsets/models.py
@@ -51,5 +51,7 @@ Traceback (most recent call last):
 Exception: <class 'regressiontests.inline_formsets.models.Child'> has no field named 'test'
 
 
+# Regression test for #9171.
+>>> ifs = inlineformset_factory(Parent, Child, exclude=('school',), fk_name='mother')
 """
 }
diff --git a/tests/regressiontests/modeladmin/models.py b/tests/regressiontests/modeladmin/models.py
index f7526ab3dd..3a7d3f031f 100644
--- a/tests/regressiontests/modeladmin/models.py
+++ b/tests/regressiontests/modeladmin/models.py
@@ -123,6 +123,14 @@ displayed because you forgot to add it to fields/fielsets
 >>> ma = BandAdmin(Band, site) 
 >>> ma.get_form(request).base_fields.keys() 
 ['name', 'sign_date']
+
+# You can also pass a tuple to `exclude`.
+ 
+>>> class BandAdmin(ModelAdmin): 
+...     exclude = ('bio',) 
+>>> ma = BandAdmin(Band, site) 
+>>> ma.get_form(request).base_fields.keys() 
+['name', 'sign_date']
  
 # Using `fields` and `exclude`.