diff --git a/tests/settings.py b/tests/settings.py
index 976cf166..d93cab20 100644
--- a/tests/settings.py
+++ b/tests/settings.py
@@ -84,7 +84,7 @@
     "toolbar": "undo redo | blocks | "
     "bold italic backcolor | alignleft aligncenter "
     "alignright alignjustify | bullist numlist outdent indent | "
-    "removeformat | help",
+    "removeformat | code | help",
 }
 
 DEFAULT_AUTO_FIELD = "django.db.models.BigAutoField"
diff --git a/tests/testapp/admin.py b/tests/testapp/admin.py
index 93ec06e8..472cb4f3 100644
--- a/tests/testapp/admin.py
+++ b/tests/testapp/admin.py
@@ -3,8 +3,8 @@
 from django.contrib.flatpages.models import FlatPage
 from django.urls import reverse
 
-from tests.testapp.models import TestInline, TestPage
-from tinymce.widgets import TinyMCE
+from tests.testapp.models import TestInline, TestModel, TestPage
+from tinymce.widgets import AdminTinyMCE
 
 
 class TinyMCETestInlineAdmin(admin.StackedInline):
@@ -14,7 +14,7 @@ class TinyMCETestInlineAdmin(admin.StackedInline):
     def formfield_for_dbfield(self, db_field, **kwargs):
         if db_field.name in ("content1", "content2"):
             return db_field.formfield(
-                widget=TinyMCE(
+                widget=AdminTinyMCE(
                     attrs={"cols": 80, "rows": 30},
                     mce_attrs={"external_link_list_url": reverse("tinymce-linklist")},
                 )
@@ -26,7 +26,7 @@ class TinyMCEFlatPageAdmin(FlatPageAdmin):
     def formfield_for_dbfield(self, db_field, **kwargs):
         if db_field.name == "content":
             return db_field.formfield(
-                widget=TinyMCE(
+                widget=AdminTinyMCE(
                     attrs={"cols": 80, "rows": 30},
                     mce_attrs={"external_link_list_url": reverse("tinymce-linklist")},
                 )
@@ -40,7 +40,7 @@ class TinyMCETestPageAdmin(admin.ModelAdmin):
     def formfield_for_dbfield(self, db_field, **kwargs):
         if db_field.name in ("content1", "content2"):
             return db_field.formfield(
-                widget=TinyMCE(
+                widget=AdminTinyMCE(
                     attrs={"cols": 80, "rows": 30},
                     mce_attrs={"external_link_list_url": reverse("tinymce-linklist")},
                 )
@@ -51,3 +51,4 @@ def formfield_for_dbfield(self, db_field, **kwargs):
 admin.site.unregister(FlatPage)
 admin.site.register(FlatPage, TinyMCEFlatPageAdmin)
 admin.site.register(TestPage, TinyMCETestPageAdmin)
+admin.site.register(TestModel)
diff --git a/tinymce/static/django_tinymce/admin_tinymce.css b/tinymce/static/django_tinymce/admin_tinymce.css
new file mode 100644
index 00000000..49f367d7
--- /dev/null
+++ b/tinymce/static/django_tinymce/admin_tinymce.css
@@ -0,0 +1,15 @@
+/*
+Workaround for the following rule defined in
+django/contrib/admin/static/admin/css/responsive.css (which is
+unsuitable for textareas used by TinyMCE internally):
+
+@media (max-width: 1024px) {
+    textarea {
+        max-width: 100%;
+        max-height: 120px;
+    }
+}
+*/
+.tox .tox-textarea-wrap .tox-textarea {
+    max-height: none;
+}
diff --git a/tinymce/widgets.py b/tinymce/widgets.py
index 65f91e0d..784b9c24 100644
--- a/tinymce/widgets.py
+++ b/tinymce/widgets.py
@@ -116,7 +116,13 @@ def _media(self):
 
 
 class AdminTinyMCE(TinyMCE, admin_widgets.AdminTextareaWidget):
-    pass
+    def _media(self):
+        css = {
+            "all": ["django_tinymce/admin_tinymce.css"],
+        }
+        return forms.Media(css=css) + super().media
+
+    media = property(_media)
 
 
 def get_language_from_django():