diff --git a/coderd/autobuild/lifecycle_executor_test.go b/coderd/autobuild/lifecycle_executor_test.go
index 3eb779376cc5c..b271fc43d1267 100644
--- a/coderd/autobuild/lifecycle_executor_test.go
+++ b/coderd/autobuild/lifecycle_executor_test.go
@@ -722,45 +722,17 @@ func TestExecutorWorkspaceAutostopNoWaitChangedMyMind(t *testing.T) {
 	err := client.UpdateWorkspaceTTL(ctx, workspace.ID, codersdk.UpdateWorkspaceTTLRequest{TTLMillis: nil})
 	require.NoError(t, err)
 
-	// Then: the deadline should still be the original value
+	// Then: the deadline should be set to zero
 	updated := coderdtest.MustWorkspace(t, client, workspace.ID)
-	assert.WithinDuration(t, workspace.LatestBuild.Deadline.Time, updated.LatestBuild.Deadline.Time, time.Minute)
+	assert.True(t, !updated.LatestBuild.Deadline.Valid)
 
 	// When: the autobuild executor ticks after the original deadline
 	go func() {
 		tickCh <- workspace.LatestBuild.Deadline.Time.Add(time.Minute)
 	}()
 
-	// Then: the workspace should stop
-	stats := <-statsCh
-	assert.Len(t, stats.Errors, 0)
-	assert.Len(t, stats.Transitions, 1)
-	assert.Equal(t, stats.Transitions[workspace.ID], database.WorkspaceTransitionStop)
-
-	// Wait for stop to complete
-	updated = coderdtest.MustWorkspace(t, client, workspace.ID)
-	_ = coderdtest.AwaitWorkspaceBuildJobCompleted(t, client, updated.LatestBuild.ID)
-
-	// Start the workspace again
-	workspace = coderdtest.MustTransitionWorkspace(t, client, workspace.ID, database.WorkspaceTransitionStop, database.WorkspaceTransitionStart)
-
-	// Given: the user changes their mind again and wants to enable autostop
-	newTTL := 8 * time.Hour
-	err = client.UpdateWorkspaceTTL(ctx, workspace.ID, codersdk.UpdateWorkspaceTTLRequest{TTLMillis: ptr.Ref(newTTL.Milliseconds())})
-	require.NoError(t, err)
-
-	// Then: the deadline should remain at the zero value
-	updated = coderdtest.MustWorkspace(t, client, workspace.ID)
-	assert.Zero(t, updated.LatestBuild.Deadline)
-
-	// When: the relentless onward march of time continues
-	go func() {
-		tickCh <- workspace.LatestBuild.Deadline.Time.Add(newTTL + time.Minute)
-		close(tickCh)
-	}()
-
 	// Then: the workspace should not stop
-	stats = <-statsCh
+	stats := <-statsCh
 	assert.Len(t, stats.Errors, 0)
 	assert.Len(t, stats.Transitions, 0)
 }
diff --git a/coderd/workspaces.go b/coderd/workspaces.go
index 19fb1ec1ce810..0e7a4b5972dfd 100644
--- a/coderd/workspaces.go
+++ b/coderd/workspaces.go
@@ -1029,6 +1029,26 @@ func (api *API) putWorkspaceTTL(rw http.ResponseWriter, r *http.Request) {
 			return xerrors.Errorf("update workspace time until shutdown: %w", err)
 		}
 
+		// If autostop has been disabled, we want to remove the deadline from the
+		// existing workspace build (if there is one).
+		if !dbTTL.Valid {
+			build, err := s.GetLatestWorkspaceBuildByWorkspaceID(ctx, workspace.ID)
+			if err != nil {
+				return xerrors.Errorf("get latest workspace build: %w", err)
+			}
+
+			if build.Transition == database.WorkspaceTransitionStart {
+				if err = s.UpdateWorkspaceBuildDeadlineByID(ctx, database.UpdateWorkspaceBuildDeadlineByIDParams{
+					ID:          build.ID,
+					Deadline:    time.Time{},
+					MaxDeadline: build.MaxDeadline,
+					UpdatedAt:   dbtime.Time(api.Clock.Now()),
+				}); err != nil {
+					return xerrors.Errorf("update workspace build deadline: %w", err)
+				}
+			}
+		}
+
 		return nil
 	}, nil)
 	if err != nil {
diff --git a/coderd/workspaces_test.go b/coderd/workspaces_test.go
index d6e365011b929..115549e28cc2b 100644
--- a/coderd/workspaces_test.go
+++ b/coderd/workspaces_test.go
@@ -2394,6 +2394,93 @@ func TestWorkspaceUpdateTTL(t *testing.T) {
 		})
 	}
 
+	t.Run("ModifyAutostopWithRunningWorkspace", func(t *testing.T) {
+		t.Parallel()
+
+		testCases := []struct {
+			name        string
+			fromTTL     *int64
+			toTTL       *int64
+			afterUpdate func(t *testing.T, before, after codersdk.NullTime)
+		}{
+			{
+				name:    "RemoveAutostopRemovesDeadline",
+				fromTTL: ptr.Ref((8 * time.Hour).Milliseconds()),
+				toTTL:   nil,
+				afterUpdate: func(t *testing.T, before, after codersdk.NullTime) {
+					require.NotZero(t, before)
+					require.Zero(t, after)
+				},
+			},
+			{
+				name:    "AddAutostopDoesNotAddDeadline",
+				fromTTL: nil,
+				toTTL:   ptr.Ref((8 * time.Hour).Milliseconds()),
+				afterUpdate: func(t *testing.T, before, after codersdk.NullTime) {
+					require.Zero(t, before)
+					require.Zero(t, after)
+				},
+			},
+			{
+				name:    "IncreaseAutostopDoesNotModifyDeadline",
+				fromTTL: ptr.Ref((4 * time.Hour).Milliseconds()),
+				toTTL:   ptr.Ref((8 * time.Hour).Milliseconds()),
+				afterUpdate: func(t *testing.T, before, after codersdk.NullTime) {
+					require.NotZero(t, before)
+					require.NotZero(t, after)
+					require.Equal(t, before, after)
+				},
+			},
+			{
+				name:    "DecreaseAutostopDoesNotModifyDeadline",
+				fromTTL: ptr.Ref((8 * time.Hour).Milliseconds()),
+				toTTL:   ptr.Ref((4 * time.Hour).Milliseconds()),
+				afterUpdate: func(t *testing.T, before, after codersdk.NullTime) {
+					require.NotZero(t, before)
+					require.NotZero(t, after)
+					require.Equal(t, before, after)
+				},
+			},
+		}
+
+		for _, testCase := range testCases {
+			testCase := testCase
+
+			t.Run(testCase.name, func(t *testing.T) {
+				t.Parallel()
+
+				var (
+					client    = coderdtest.New(t, &coderdtest.Options{IncludeProvisionerDaemon: true})
+					user      = coderdtest.CreateFirstUser(t, client)
+					version   = coderdtest.CreateTemplateVersion(t, client, user.OrganizationID, nil)
+					_         = coderdtest.AwaitTemplateVersionJobCompleted(t, client, version.ID)
+					template  = coderdtest.CreateTemplate(t, client, user.OrganizationID, version.ID)
+					workspace = coderdtest.CreateWorkspace(t, client, template.ID, func(cwr *codersdk.CreateWorkspaceRequest) {
+						cwr.TTLMillis = testCase.fromTTL
+					})
+					build = coderdtest.AwaitWorkspaceBuildJobCompleted(t, client, workspace.LatestBuild.ID)
+				)
+
+				ctx, cancel := context.WithTimeout(context.Background(), testutil.WaitLong)
+				defer cancel()
+
+				err := client.UpdateWorkspaceTTL(ctx, workspace.ID, codersdk.UpdateWorkspaceTTLRequest{
+					TTLMillis: testCase.toTTL,
+				})
+				require.NoError(t, err)
+
+				deadlineBefore := build.Deadline
+
+				build, err = client.WorkspaceBuild(ctx, build.ID)
+				require.NoError(t, err)
+
+				deadlineAfter := build.Deadline
+
+				testCase.afterUpdate(t, deadlineBefore, deadlineAfter)
+			})
+		}
+	})
+
 	t.Run("CustomAutostopDisabledByTemplate", func(t *testing.T) {
 		t.Parallel()
 		var (
diff --git a/site/src/pages/WorkspaceSettingsPage/WorkspaceSchedulePage/WorkspaceSchedulePage.tsx b/site/src/pages/WorkspaceSettingsPage/WorkspaceSchedulePage/WorkspaceSchedulePage.tsx
index b5e9bfdba8da6..4ee96204dbdd5 100644
--- a/site/src/pages/WorkspaceSettingsPage/WorkspaceSchedulePage/WorkspaceSchedulePage.tsx
+++ b/site/src/pages/WorkspaceSettingsPage/WorkspaceSchedulePage/WorkspaceSchedulePage.tsx
@@ -118,7 +118,10 @@ export const WorkspaceSchedulePage: FC = () => {
 
 						await submitScheduleMutation.mutateAsync(data);
 
-						if (data.autostopChanged) {
+						if (
+							data.autostopChanged &&
+							getAutostop(workspace).autostopEnabled
+						) {
 							setIsConfirmingApply(true);
 						}
 					}}