diff --git a/modules/markup/html.go b/modules/markup/html.go
index da16bcd3cb..e53ccc6a79 100644
--- a/modules/markup/html.go
+++ b/modules/markup/html.go
@@ -852,7 +852,7 @@ func fullIssuePatternProcessor(ctx *RenderContext, node *html.Node) {
 }
 
 func issueIndexPatternProcessor(ctx *RenderContext, node *html.Node) {
-	if ctx.Metas == nil {
+	if ctx.Metas == nil || ctx.Metas["mode"] == "document" {
 		return
 	}
 	var (
diff --git a/modules/markup/html_internal_test.go b/modules/markup/html_internal_test.go
index 00ffe45c28..7b7f6df701 100644
--- a/modules/markup/html_internal_test.go
+++ b/modules/markup/html_internal_test.go
@@ -262,6 +262,30 @@ func TestRender_IssueIndexPattern5(t *testing.T) {
 	})
 }
 
+func TestRender_IssueIndexPattern_Document(t *testing.T) {
+	setting.AppURL = TestAppURL
+	metas := map[string]string{
+		"format": "https://someurl.com/{user}/{repo}/{index}",
+		"user":   "someUser",
+		"repo":   "someRepo",
+		"style":  IssueNameStyleNumeric,
+		"mode":   "document",
+	}
+
+	testRenderIssueIndexPattern(t, "#1", "#1", &RenderContext{
+		Ctx:   git.DefaultContext,
+		Metas: metas,
+	})
+	testRenderIssueIndexPattern(t, "#1312", "#1312", &RenderContext{
+		Ctx:   git.DefaultContext,
+		Metas: metas,
+	})
+	testRenderIssueIndexPattern(t, "!1", "!1", &RenderContext{
+		Ctx:   git.DefaultContext,
+		Metas: metas,
+	})
+}
+
 func testRenderIssueIndexPattern(t *testing.T, input, expected string, ctx *RenderContext) {
 	if ctx.URLPrefix == "" {
 		ctx.URLPrefix = TestAppURL
diff --git a/modules/markup/html_test.go b/modules/markup/html_test.go
index a8d7ba7948..9156bc6331 100644
--- a/modules/markup/html_test.go
+++ b/modules/markup/html_test.go
@@ -529,6 +529,42 @@ func Test_ParseClusterFuzz(t *testing.T) {
 	assert.NotContains(t, res.String(), "<html")
 }
 
+func TestPostProcess_RenderDocument(t *testing.T) {
+	setting.AppURL = TestAppURL
+
+	localMetas := map[string]string{
+		"user": "go-gitea",
+		"repo": "gitea",
+		"mode": "document",
+	}
+
+	test := func(input, expected string) {
+		var res strings.Builder
+		err := PostProcess(&RenderContext{
+			Ctx:       git.DefaultContext,
+			URLPrefix: "https://example.com",
+			Metas:     localMetas,
+		}, strings.NewReader(input), &res)
+		assert.NoError(t, err)
+		assert.Equal(t, strings.TrimSpace(expected), strings.TrimSpace(res.String()))
+	}
+
+	// Issue index shouldn't be post processing in an document.
+	test(
+		"#1",
+		"#1")
+
+	// Test that other post processing still works.
+	test(
+		":gitea:",
+		`<span class="emoji" aria-label="gitea"><img alt=":gitea:" src="`+setting.StaticURLPrefix+`/assets/img/emoji/gitea.png"/></span>`)
+	test(
+		"Some text with 😄 in the middle",
+		`Some text with <span class="emoji" aria-label="grinning face with smiling eyes">😄</span> in the middle`)
+	test("http://localhost:3000/person/repo/issues/4#issuecomment-1234",
+		`<a href="http://localhost:3000/person/repo/issues/4#issuecomment-1234" class="ref-issue">person/repo#4 (comment)</a>`)
+}
+
 func TestIssue16020(t *testing.T) {
 	setting.AppURL = TestAppURL