diff --git a/ram/bookshelf/admin.py b/ram/bookshelf/admin.py
index 0e8a88b..a5bf51c 100644
--- a/ram/bookshelf/admin.py
+++ b/ram/bookshelf/admin.py
@@ -2,7 +2,7 @@ import html
 
 from django.conf import settings
 from django.contrib import admin
-from django.utils.html import format_html, strip_tags
+from django.utils.html import format_html, format_html_join, strip_tags
 from adminsortable2.admin import SortableAdminBase, SortableInlineAdminMixin
 
 from ram.admin import publish, unpublish
@@ -123,13 +123,14 @@ class BookAdmin(SortableAdminBase, admin.ModelAdmin):
     @admin.display(description="Invoices")
     def invoices(self, obj):
         if obj.invoice.exists():
-            html = "<br>".join(
-                "<a href=\"{}\" target=\"_blank\">{}</a>".format(
-                    i.file.url, i
-                ) for i in obj.invoice.all())
+            html = format_html_join(
+                "<br>",
+                "<a href=\"{}\" target=\"_blank\">{}</a>",
+                ((i.file.url, i) for i in obj.invoice.all())
+            )
         else:
             html = "-"
-        return format_html(html)
+        return html
 
     @admin.display(description="Publisher")
     def get_publisher(self, obj):
@@ -207,7 +208,7 @@ class PublisherAdmin(admin.ModelAdmin):
     @admin.display(description="Country")
     def country_flag(self, obj):
         return format_html(
-            '<img src="{}" /> {}'.format(obj.country.flag, obj.country.name)
+            '<img src="{}" /> {}', obj.country.flag, obj.country.name
         )
 
 
@@ -285,13 +286,14 @@ class CatalogAdmin(SortableAdminBase, admin.ModelAdmin):
     @admin.display(description="Invoices")
     def invoices(self, obj):
         if obj.invoice.exists():
-            html = "<br>".join(
-                "<a href=\"{}\" target=\"_blank\">{}</a>".format(
-                    i.file.url, i
-                ) for i in obj.invoice.all())
+            html = format_html_join(
+                "<br>",
+                "<a href=\"{}\" target=\"_blank\">{}</a>",
+                ((i.file.url, i) for i in obj.invoice.all())
+            )
         else:
             html = "-"
-        return format_html(html)
+        return html
 
     def download_csv(modeladmin, request, queryset):
         header = [
diff --git a/ram/consist/admin.py b/ram/consist/admin.py
index 472b6a0..135760a 100644
--- a/ram/consist/admin.py
+++ b/ram/consist/admin.py
@@ -54,7 +54,7 @@ class ConsistAdmin(SortableAdminBase, admin.ModelAdmin):
     @admin.display(description="Country")
     def country_flag(self, obj):
         return format_html(
-            '<img src="{}" /> {}'.format(obj.country.flag, obj.country)
+            '<img src="{}" /> {}', obj.country.flag, obj.country
         )
 
     fieldsets = (
diff --git a/ram/metadata/admin.py b/ram/metadata/admin.py
index c017394..d3f30b5 100644
--- a/ram/metadata/admin.py
+++ b/ram/metadata/admin.py
@@ -54,7 +54,7 @@ class CompanyAdmin(admin.ModelAdmin):
     @admin.display(description="Country")
     def country_flag(self, obj):
         return format_html(
-            '<img src="{}" /> {}'.format(obj.country.flag, obj.country.name)
+            '<img src="{}" /> {}', obj.country.flag, obj.country.name
         )
 
 
@@ -68,7 +68,7 @@ class ManufacturerAdmin(admin.ModelAdmin):
     @admin.display(description="Country")
     def country_flag(self, obj):
         return format_html(
-            '<img src="{}" /> {}'.format(obj.country.flag, obj.country.name)
+            '<img src="{}" /> {}', obj.country.flag, obj.country.name
         )
 
 
diff --git a/ram/ram/utils.py b/ram/ram/utils.py
index b5c5e94..f60b1f3 100644
--- a/ram/ram/utils.py
+++ b/ram/ram/utils.py
@@ -48,8 +48,9 @@ def git_suffix(fname):
 
 def get_image_preview(url, max_size=150):
     return format_html(
-        '<img src="{src}" style="max-width: {size}px; max-height: {size}px;'
-        'background-color: #eee;" />'.format(src=url, size=max_size)
+        '<img src="{src}" style="max-width: {size}px; max-height: {size}px; background-color: #eee;" />',  # noqa: E501
+        src=url,
+        size=max_size,
     )
 
 
diff --git a/ram/roster/admin.py b/ram/roster/admin.py
index e7908fa..9d291e2 100644
--- a/ram/roster/admin.py
+++ b/ram/roster/admin.py
@@ -2,7 +2,7 @@ import html
 
 from django.conf import settings
 from django.contrib import admin
-from django.utils.html import format_html, strip_tags
+from django.utils.html import format_html, format_html_join, strip_tags
 
 from adminsortable2.admin import SortableAdminBase, SortableInlineAdminMixin
 
@@ -44,7 +44,7 @@ class RollingClass(admin.ModelAdmin):
     @admin.display(description="Country")
     def country_flag(self, obj):
         return format_html(
-            '<img src="{}" /> {}'.format(obj.country.flag, obj.country)
+            '<img src="{}" /> {}', obj.country.flag, obj.country.name
         )
 
 
@@ -152,7 +152,7 @@ class RollingStockAdmin(SortableAdminBase, admin.ModelAdmin):
     @admin.display(description="Country")
     def country_flag(self, obj):
         return format_html(
-            '<img src="{}" /> {}'.format(obj.country.flag, obj.country)
+            '<img src="{}" /> {}', obj.country.flag, obj.country.name
         )
 
     fieldsets = (
@@ -222,13 +222,14 @@ class RollingStockAdmin(SortableAdminBase, admin.ModelAdmin):
     @admin.display(description="Invoices")
     def invoices(self, obj):
         if obj.invoice.exists():
-            html = "<br>".join(
-                "<a href=\"{}\" target=\"_blank\">{}</a>".format(
-                    i.file.url, i
-                ) for i in obj.invoice.all())
+            html = format_html_join(
+                "<br>",
+                "<a href=\"{}\" target=\"_blank\">{}</a>",
+                ((i.file.url, i) for i in obj.invoice.all())
+            )
         else:
             html = "-"
-        return format_html(html)
+        return html
 
     def download_csv(modeladmin, request, queryset):
         header = [