diff --git a/pkg/commands/git_commands/worktree_loader.go b/pkg/commands/git_commands/worktree_loader.go
index f7577c870..ed5dc2f46 100644
--- a/pkg/commands/git_commands/worktree_loader.go
+++ b/pkg/commands/git_commands/worktree_loader.go
@@ -140,12 +140,14 @@ func (self *WorktreeLoader) GetWorktrees() ([]*models.Worktree, error) {
 		rebasedBranch, ok := self.rebasedBranch(worktree)
 		if ok {
 			worktree.Branch = rebasedBranch
+			worktree.IsRebasingOrBisecting = true
 			continue
 		}
 
 		bisectedBranch, ok := self.bisectedBranch(worktree)
 		if ok {
 			worktree.Branch = bisectedBranch
+			worktree.IsRebasingOrBisecting = true
 			continue
 		}
 	}
diff --git a/pkg/commands/models/worktree.go b/pkg/commands/models/worktree.go
index 053a3f101..a1f00f95d 100644
--- a/pkg/commands/models/worktree.go
+++ b/pkg/commands/models/worktree.go
@@ -19,6 +19,9 @@ type Worktree struct {
 	// * the worktree is mid-rebase on the branch
 	// * the worktree is mid-bisect on the branch
 	Branch string
+	// If true, the worktree is mid-rebase or mid-bisect on Branch, so its HEAD
+	// is detached rather than pointing at the branch
+	IsRebasingOrBisecting bool
 	// The HEAD sha of the worktree. Always populated (even when Branch is set).
 	// Used for display when Branch is empty (detached HEAD state).
 	Head string
diff --git a/pkg/gui/controllers/helpers/branches_helper.go b/pkg/gui/controllers/helpers/branches_helper.go
index 29c27f93e..e3586fa52 100644
--- a/pkg/gui/controllers/helpers/branches_helper.go
+++ b/pkg/gui/controllers/helpers/branches_helper.go
@@ -457,6 +457,17 @@ func (self *BranchesHelper) FastForwardBranches(branches []*models.Branch) error
 	})
 	anyCheckedOut := lo.SomeBy(toForward, func(f *branchToForward) bool { return f.worktree != nil })
 
+	// Updating that worktree would move its detached HEAD, which belongs to the
+	// rebase or bisect, and leave the branch alone
+	for _, f := range toForward {
+		if f.worktree != nil && f.worktree.IsRebasingOrBisecting {
+			return errors.New(utils.ResolvePlaceholderString(
+				self.c.Tr.FwdBranchRebasingOrBisecting,
+				map[string]string{"branchName": f.branch.Name, "worktreeName": f.worktree.Name},
+			))
+		}
+	}
+
 	return self.withFastForwardingStatus(branches, func(task gocui.Task) error {
 		defer func() {
 			if anyCheckedOut {
diff --git a/pkg/i18n/english.go b/pkg/i18n/english.go
index 0a324a14a..3cfe7bd78 100644
--- a/pkg/i18n/english.go
+++ b/pkg/i18n/english.go
@@ -376,6 +376,7 @@ type TranslationSet struct {
 	FwdCommitsToPush                      string
 	FwdLocalOnlyCommits                   string
 	FwdUncommittedChanges                 string
+	FwdBranchRebasingOrBisecting          string
 	PullRequestNoUpstream                 string
 	PullRequestChecksPassing              string
 	PullRequestChecksPending              string
@@ -1551,6 +1552,7 @@ func EnglishTranslationSet() *TranslationSet {
 		FwdCommitsToPush:                     "Cannot fast-forward a branch with commits to push",
 		FwdLocalOnlyCommits:                  "Cannot fast-forward '{{.branchName}}' because it has commits which were never on its remote branch",
 		FwdUncommittedChanges:                "Cannot fast-forward '{{.branchName}}' because the worktree it is checked out in has uncommitted changes",
+		FwdBranchRebasingOrBisecting:         "Cannot fast-forward '{{.branchName}}' because it is being rebased or bisected in worktree {{.worktreeName}}",
 		PullRequestNoUpstream:                "Cannot open a pull request for a branch with no upstream",
 		PullRequestChecksPassing:             "Passing",
 		PullRequestChecksPending:             "Pending",
diff --git a/pkg/integration/tests/sync/fast_forward_branch_being_rebased_in_worktree.go b/pkg/integration/tests/sync/fast_forward_branch_being_rebased_in_worktree.go
index 2d59589fd..dabcc5dac 100644
--- a/pkg/integration/tests/sync/fast_forward_branch_being_rebased_in_worktree.go
+++ b/pkg/integration/tests/sync/fast_forward_branch_being_rebased_in_worktree.go
@@ -39,12 +39,10 @@ var FastForwardBranchBeingRebasedInWorktree = NewIntegrationTest(NewIntegrationT
 			NavigateToLine(Contains("master")).
 			Press(keys.Branches.FastForward)
 
-		/* EXPECTED:
 		t.ExpectPopup().Alert().
 			Title(Equals("Error")).
 			Content(Equals("Cannot fast-forward 'master' because it is being rebased or bisected in worktree linked-worktree")).
 			Confirm()
-		ACTUAL: */
 
 		t.Views().Worktrees().
 			Focus().
@@ -57,11 +55,6 @@ var FastForwardBranchBeingRebasedInWorktree = NewIntegrationTest(NewIntegrationT
 			Lines(
 				Contains("─── Pending rebase todos"),
 				Contains("─── Commits"),
-				/* EXPECTED:
-				Contains("two"),
-				Contains("one"),
-				ACTUAL: */
-				Contains("three"),
 				Contains("two"),
 				Contains("one"),
 			)