diff --git a/routers/web/feed/convert.go b/routers/web/feed/convert.go
index 0f4334692f..d3d01a87e0 100644
--- a/routers/web/feed/convert.go
+++ b/routers/web/feed/convert.go
@@ -13,7 +13,9 @@ import (
 	"strings"
 
 	activities_model "code.gitea.io/gitea/models/activities"
+	issues_model "code.gitea.io/gitea/models/issues"
 	repo_model "code.gitea.io/gitea/models/repo"
+	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/markup"
 	"code.gitea.io/gitea/modules/markup/markdown"
 	"code.gitea.io/gitea/modules/setting"
@@ -232,6 +234,16 @@ func feedActionsToFeedItems(ctx *context.Context, actions activities_model.Actio
 			case activities_model.ActionCommentIssue, activities_model.ActionApprovePullRequest, activities_model.ActionRejectPullRequest, activities_model.ActionCommentPull:
 				desc = act.GetIssueTitle(ctx)
 				comment := act.GetIssueInfos()[1]
+				if strings.HasSuffix(comment, "…") {
+					// Comment was truncated get the full content from the database.
+					// This truncation is done in `NotifyCreateIssueComment`.
+					commentModel, err := issues_model.GetCommentByID(ctx, act.CommentID)
+					if err != nil {
+						log.Error("Couldn't get comment[%d] for RSS feed: %v", act.CommentID, err)
+					} else {
+						comment = commentModel.Content
+					}
+				}
 				if len(comment) != 0 {
 					desc += "\n\n" + string(renderMarkdown(ctx, act, comment))
 				}
diff --git a/tests/integration/api_feed_user_test.go b/tests/integration/api_feed_user_test.go
index 7f3824963a..3fa9b86150 100644
--- a/tests/integration/api_feed_user_test.go
+++ b/tests/integration/api_feed_user_test.go
@@ -16,6 +16,7 @@ import (
 )
 
 func TestFeed(t *testing.T) {
+	defer tests.AddFixtures("tests/integration/fixtures/TestFeed/")()
 	defer tests.PrepareTestEnv(t)()
 
 	t.Run("User", func(t *testing.T) {
@@ -42,6 +43,28 @@ func TestFeed(t *testing.T) {
 
 	t.Run("Repo", func(t *testing.T) {
 		t.Run("Normal", func(t *testing.T) {
+			t.Run("Atom", func(t *testing.T) {
+				defer tests.PrintCurrentTest(t)()
+
+				req := NewRequest(t, "GET", "/user2/repo1.atom")
+				resp := MakeRequest(t, req, http.StatusOK)
+
+				data := resp.Body.String()
+				assert.Contains(t, data, `<feed xmlns="http://www.w3.org/2005/Atom"`)
+				assert.Contains(t, data, "This is a very long text, so lets scream together: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
+			})
+			t.Run("RSS", func(t *testing.T) {
+				defer tests.PrintCurrentTest(t)()
+
+				req := NewRequest(t, "GET", "/user2/repo1.rss")
+				resp := MakeRequest(t, req, http.StatusOK)
+
+				data := resp.Body.String()
+				assert.Contains(t, data, `<rss version="2.0"`)
+				assert.Contains(t, data, "This is a very long text, so lets scream together: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
+			})
+		})
+		t.Run("Branch", func(t *testing.T) {
 			t.Run("Atom", func(t *testing.T) {
 				defer tests.PrintCurrentTest(t)()
 
diff --git a/tests/integration/fixtures/TestFeed/action.yml b/tests/integration/fixtures/TestFeed/action.yml
new file mode 100644
index 0000000000..c00e4bcc59
--- /dev/null
+++ b/tests/integration/fixtures/TestFeed/action.yml
@@ -0,0 +1,9 @@
+- id: 1001
+  user_id: 2
+  op_type: 10 # close issue
+  act_user_id: 2
+  comment_id: 1001
+  repo_id: 1 # public
+  is_private: false
+  created_unix: 1680454039
+  content: '1|This is a very long text, so lets scream together: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa…'
diff --git a/tests/integration/fixtures/TestFeed/comment.yml b/tests/integration/fixtures/TestFeed/comment.yml
new file mode 100644
index 0000000000..bfa0c8c3ef
--- /dev/null
+++ b/tests/integration/fixtures/TestFeed/comment.yml
@@ -0,0 +1,8 @@
+-
+  id: 1001
+  type: 0 # comment
+  poster_id: 2
+  issue_id: 1 # in repo_id 1
+  content: "This is a very long text, so lets scream together: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+  created_unix: 1729602027
+  updated_unix: 1729602027