diff --git a/release-notes/8.0.0/fix/3562.md b/release-notes/8.0.0/fix/3562.md
new file mode 100644
index 0000000000..8099056205
--- /dev/null
+++ b/release-notes/8.0.0/fix/3562.md
@@ -0,0 +1 @@
+Fixed a bug where subscribing to or unsubscribing from an issue in a repository with no code produced an internal server error.
diff --git a/routers/web/repo/issue_watch.go b/routers/web/repo/issue_watch.go
index 8b033f3b17..6799bf8eb2 100644
--- a/routers/web/repo/issue_watch.go
+++ b/routers/web/repo/issue_watch.go
@@ -46,7 +46,7 @@ func IssueWatch(ctx *context.Context) {
 		return
 	}
 
-	watch, err := strconv.ParseBool(ctx.Req.PostForm.Get("watch"))
+	watch, err := strconv.ParseBool(ctx.Req.PostFormValue("watch"))
 	if err != nil {
 		ctx.ServerError("watch is not bool", err)
 		return
diff --git a/tests/integration/integration_test.go b/tests/integration/integration_test.go
index 8fd55d7fa8..f1c6b9f135 100644
--- a/tests/integration/integration_test.go
+++ b/tests/integration/integration_test.go
@@ -36,6 +36,7 @@ import (
 	"code.gitea.io/gitea/modules/graceful"
 	"code.gitea.io/gitea/modules/json"
 	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/optional"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/testlogger"
 	"code.gitea.io/gitea/modules/util"
@@ -45,6 +46,7 @@ import (
 	repo_service "code.gitea.io/gitea/services/repository"
 	files_service "code.gitea.io/gitea/services/repository/files"
 	user_service "code.gitea.io/gitea/services/user"
+	wiki_service "code.gitea.io/gitea/services/wiki"
 	"code.gitea.io/gitea/tests"
 
 	"github.com/PuerkitoBio/goquery"
@@ -652,19 +654,39 @@ func GetHTMLTitle(t testing.TB, session *TestSession, urlStr string) string {
 	return doc.Find("head title").Text()
 }
 
-func CreateDeclarativeRepo(t *testing.T, owner *user_model.User, name string, enabledUnits, disabledUnits []unit_model.Type, files []*files_service.ChangeRepoFile) (*repo_model.Repository, string, func()) {
+type DeclarativeRepoOptions struct {
+	Name          optional.Option[string]
+	EnabledUnits  optional.Option[[]unit_model.Type]
+	DisabledUnits optional.Option[[]unit_model.Type]
+	Files         optional.Option[[]*files_service.ChangeRepoFile]
+	WikiBranch    optional.Option[string]
+	AutoInit      optional.Option[bool]
+}
+
+func CreateDeclarativeRepoWithOptions(t *testing.T, owner *user_model.User, opts DeclarativeRepoOptions) (*repo_model.Repository, string, func()) {
 	t.Helper()
 
-	repoName := name
-	if repoName == "" {
+	// Not using opts.Name.ValueOrDefault() here to avoid unnecessarily
+	// generating an UUID when a name is specified.
+	var repoName string
+	if opts.Name.Has() {
+		repoName = opts.Name.Value()
+	} else {
 		repoName = gouuid.NewString()
 	}
 
-	// Create a new repository
+	var autoInit bool
+	if opts.AutoInit.Has() {
+		autoInit = opts.AutoInit.Value()
+	} else {
+		autoInit = true
+	}
+
+	// Create the repository
 	repo, err := repo_service.CreateRepository(db.DefaultContext, owner, owner, repo_service.CreateRepoOptions{
 		Name:          repoName,
 		Description:   "Temporary Repo",
-		AutoInit:      true,
+		AutoInit:      autoInit,
 		Gitignores:    "",
 		License:       "WTFPL",
 		Readme:        "Default",
@@ -673,21 +695,32 @@ func CreateDeclarativeRepo(t *testing.T, owner *user_model.User, name string, en
 	assert.NoError(t, err)
 	assert.NotEmpty(t, repo)
 
-	if enabledUnits != nil || disabledUnits != nil {
-		units := make([]repo_model.RepoUnit, len(enabledUnits))
-		for i, unitType := range enabledUnits {
-			units[i] = repo_model.RepoUnit{
+	// Populate `enabledUnits` if we have any enabled.
+	var enabledUnits []repo_model.RepoUnit
+	if opts.EnabledUnits.Has() {
+		units := opts.EnabledUnits.Value()
+		enabledUnits = make([]repo_model.RepoUnit, len(units))
+
+		for i, unitType := range units {
+			enabledUnits[i] = repo_model.RepoUnit{
 				RepoID: repo.ID,
 				Type:   unitType,
 			}
 		}
+	}
 
-		err := repo_service.UpdateRepositoryUnits(db.DefaultContext, repo, units, disabledUnits)
+	// Adjust the repo units according to our parameters.
+	if opts.EnabledUnits.Has() || opts.DisabledUnits.Has() {
+		err := repo_service.UpdateRepositoryUnits(db.DefaultContext, repo, enabledUnits, opts.DisabledUnits.ValueOrDefault(nil))
 		assert.NoError(t, err)
 	}
 
+	// Add files, if any.
 	var sha string
-	if len(files) > 0 {
+	if opts.Files.Has() {
+		assert.True(t, autoInit, "Files cannot be specified if AutoInit is disabled")
+		files := opts.Files.Value()
+
 		resp, err := files_service.ChangeRepoFiles(git.DefaultContext, repo, owner, &files_service.ChangeRepoFilesOptions{
 			Files:     files,
 			Message:   "add files",
@@ -712,7 +745,46 @@ func CreateDeclarativeRepo(t *testing.T, owner *user_model.User, name string, en
 		sha = resp.Commit.SHA
 	}
 
+	// If there's a Wiki branch specified, create a wiki, and a default wiki page.
+	if opts.WikiBranch.Has() {
+		// Set the wiki branch in the database first
+		repo.WikiBranch = opts.WikiBranch.Value()
+		err := repo_model.UpdateRepositoryCols(db.DefaultContext, repo, "wiki_branch")
+		assert.NoError(t, err)
+
+		// Initialize the wiki
+		err = wiki_service.InitWiki(db.DefaultContext, repo)
+		assert.NoError(t, err)
+
+		// Add a new wiki page
+		err = wiki_service.AddWikiPage(db.DefaultContext, owner, repo, "Home", "Welcome to the wiki!", "Add a Home page")
+		assert.NoError(t, err)
+	}
+
+	// Return the repo, the top commit, and a defer-able function to delete the
+	// repo.
 	return repo, sha, func() {
 		repo_service.DeleteRepository(db.DefaultContext, owner, repo, false)
 	}
 }
+
+func CreateDeclarativeRepo(t *testing.T, owner *user_model.User, name string, enabledUnits, disabledUnits []unit_model.Type, files []*files_service.ChangeRepoFile) (*repo_model.Repository, string, func()) {
+	t.Helper()
+
+	var opts DeclarativeRepoOptions
+
+	if name != "" {
+		opts.Name = optional.Some(name)
+	}
+	if enabledUnits != nil {
+		opts.EnabledUnits = optional.Some(enabledUnits)
+	}
+	if disabledUnits != nil {
+		opts.DisabledUnits = optional.Some(disabledUnits)
+	}
+	if files != nil {
+		opts.Files = optional.Some(files)
+	}
+
+	return CreateDeclarativeRepoWithOptions(t, owner, opts)
+}
diff --git a/tests/integration/issue_test.go b/tests/integration/issue_test.go
index 84487a847a..94ba670b71 100644
--- a/tests/integration/issue_test.go
+++ b/tests/integration/issue_test.go
@@ -22,6 +22,7 @@ import (
 	"code.gitea.io/gitea/models/unittest"
 	user_model "code.gitea.io/gitea/models/user"
 	"code.gitea.io/gitea/modules/indexer/issues"
+	"code.gitea.io/gitea/modules/optional"
 	"code.gitea.io/gitea/modules/references"
 	"code.gitea.io/gitea/modules/setting"
 	api "code.gitea.io/gitea/modules/structs"
@@ -866,3 +867,23 @@ body:
 		})
 	})
 }
+
+func TestIssueUnsubscription(t *testing.T) {
+	onGiteaRun(t, func(t *testing.T, u *url.URL) {
+		defer tests.PrepareTestEnv(t)()
+
+		user := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: 1})
+		repo, _, f := CreateDeclarativeRepoWithOptions(t, user, DeclarativeRepoOptions{
+			AutoInit: optional.Some(false),
+		})
+		defer f()
+		session := loginUser(t, user.Name)
+
+		issueURL := testNewIssue(t, session, user.Name, repo.Name, "Issue title", "Description")
+		req := NewRequestWithValues(t, "POST", fmt.Sprintf("%s/watch", issueURL), map[string]string{
+			"_csrf": GetCSRF(t, session, issueURL),
+			"watch": "0",
+		})
+		session.MakeRequest(t, req, http.StatusOK)
+	})
+}