diff --git a/activitypub.go b/activitypub.go
index 0308b6c..0ac4d0c 100644
--- a/activitypub.go
+++ b/activitypub.go
@@ -80,6 +80,7 @@ func handleFetchCollectionActivities(app *App, w http.ResponseWriter, r *http.Re
 	if err != nil {
 		return err
 	}
+	c.hostName = app.cfg.App.Host
 
 	p := c.PersonObject()
 
@@ -104,6 +105,7 @@ func handleFetchCollectionOutbox(app *App, w http.ResponseWriter, r *http.Reques
 	if err != nil {
 		return err
 	}
+	c.hostName = app.cfg.App.Host
 
 	if app.cfg.App.SingleUser {
 		if alias != c.Alias {
@@ -156,6 +158,7 @@ func handleFetchCollectionFollowers(app *App, w http.ResponseWriter, r *http.Req
 	if err != nil {
 		return err
 	}
+	c.hostName = app.cfg.App.Host
 
 	accountRoot := c.FederatedAccount()
 
@@ -201,6 +204,7 @@ func handleFetchCollectionFollowing(app *App, w http.ResponseWriter, r *http.Req
 	if err != nil {
 		return err
 	}
+	c.hostName = app.cfg.App.Host
 
 	accountRoot := c.FederatedAccount()
 
@@ -234,6 +238,7 @@ func handleFetchCollectionInbox(app *App, w http.ResponseWriter, r *http.Request
 		// TODO: return Reject?
 		return err
 	}
+	c.hostName = app.cfg.App.Host
 
 	if debugging {
 		dump, err := httputil.DumpRequest(r, true)
@@ -349,7 +354,7 @@ func handleFetchCollectionInbox(app *App, w http.ResponseWriter, r *http.Request
 			log.Error("No to! %v", err)
 			return
 		}
-		err = makeActivityPost(p, fullActor.Inbox, am)
+		err = makeActivityPost(app.cfg.App.Host, p, fullActor.Inbox, am)
 		if err != nil {
 			log.Error("Unable to make activity POST: %v", err)
 			return
@@ -423,7 +428,7 @@ func handleFetchCollectionInbox(app *App, w http.ResponseWriter, r *http.Request
 	return nil
 }
 
-func makeActivityPost(p *activitystreams.Person, url string, m interface{}) error {
+func makeActivityPost(hostName string, p *activitystreams.Person, url string, m interface{}) error {
 	log.Info("POST %s", url)
 	b, err := json.Marshal(m)
 	if err != nil {
@@ -477,7 +482,7 @@ func makeActivityPost(p *activitystreams.Person, url string, m interface{}) erro
 	return nil
 }
 
-func resolveIRI(url string) ([]byte, error) {
+func resolveIRI(hostName, url string) ([]byte, error) {
 	log.Info("GET %s", url)
 
 	r, _ := http.NewRequest("GET", url, nil)
@@ -547,7 +552,7 @@ func deleteFederatedPost(app *App, p *PublicPost, collID int64) error {
 			na.CC = append(na.CC, f)
 		}
 
-		err = makeActivityPost(actor, si, activitystreams.NewDeleteActivity(na))
+		err = makeActivityPost(app.cfg.App.Host, actor, si, activitystreams.NewDeleteActivity(na))
 		if err != nil {
 			log.Error("Couldn't delete post! %v", err)
 		}
@@ -601,7 +606,7 @@ func federatePost(app *App, p *PublicPost, collID int64, isUpdate bool) error {
 			activity.To = na.To
 			activity.CC = na.CC
 		}
-		err = makeActivityPost(actor, si, activity)
+		err = makeActivityPost(app.cfg.App.Host, actor, si, activity)
 		if err != nil {
 			log.Error("Couldn't post! %v", err)
 		}
@@ -632,7 +637,7 @@ func getActor(app *App, actorIRI string) (*activitystreams.Person, *RemoteUser,
 			if iErr.Status == http.StatusNotFound {
 				// Fetch remote actor
 				log.Info("Not found; fetching actor %s remotely", actorIRI)
-				actorResp, err := resolveIRI(actorIRI)
+				actorResp, err := resolveIRI(app.cfg.App.Host, actorIRI)
 				if err != nil {
 					log.Error("Unable to get actor! %v", err)
 					return nil, nil, impart.HTTPError{http.StatusInternalServerError, "Couldn't fetch actor."}
diff --git a/app.go b/app.go
index e970a77..a0864c4 100644
--- a/app.go
+++ b/app.go
@@ -57,9 +57,6 @@ var (
 	softwareVer = "0.9.0"
 
 	// DEPRECATED VARS
-	// TODO: pass app.cfg into GetCollection* calls so we can get these values
-	// from Collection methods and we no longer need these.
-	hostName     string
 	isSingleUser bool
 )
 
@@ -338,7 +335,6 @@ func Initialize(apper Apper, debug bool) (*App, error) {
 func Serve(app *App, r *mux.Router) {
 	log.Info("Going to serve...")
 
-	hostName = app.cfg.App.Host
 	isSingleUser = app.cfg.App.SingleUser
 	app.cfg.Server.Dev = debugging
 
diff --git a/collections.go b/collections.go
index eb9fcab..1a8ceca 100644
--- a/collections.go
+++ b/collections.go
@@ -54,7 +54,8 @@ type (
 		PublicOwner bool           `datastore:"public_owner" json:"-"`
 		URL         string         `json:"url,omitempty"`
 
-		db *datastore
+		db       *datastore
+		hostName string
 	}
 	CollectionObj struct {
 		Collection
@@ -211,10 +212,10 @@ func (c *Collection) DisplayCanonicalURL() string {
 
 func (c *Collection) RedirectingCanonicalURL(isRedir bool) string {
 	if isSingleUser {
-		return hostName + "/"
+		return c.hostName + "/"
 	}
 
-	return fmt.Sprintf("%s/%s/", hostName, c.Alias)
+	return fmt.Sprintf("%s/%s/", c.hostName, c.Alias)
 }
 
 // PrevPageURL provides a full URL for the previous page of collection posts,
@@ -300,11 +301,11 @@ func (c *Collection) AvatarURL() string {
 	if !isAvatarChar(fl) {
 		return ""
 	}
-	return hostName + "/img/avatars/" + fl + ".png"
+	return c.hostName + "/img/avatars/" + fl + ".png"
 }
 
 func (c *Collection) FederatedAPIBase() string {
-	return hostName + "/"
+	return c.hostName + "/"
 }
 
 func (c *Collection) FederatedAccount() string {
@@ -434,6 +435,8 @@ func fetchCollection(app *App, w http.ResponseWriter, r *http.Request) error {
 	if err != nil {
 		return err
 	}
+	c.hostName = app.cfg.App.Host
+
 	// Redirect users who aren't requesting JSON
 	reqJSON := IsJSON(r.Header.Get("Content-Type"))
 	if !reqJSON {
@@ -475,6 +478,7 @@ func fetchCollectionPosts(app *App, w http.ResponseWriter, r *http.Request) erro
 	if err != nil {
 		return err
 	}
+	c.hostName = app.cfg.App.Host
 
 	// Check permissions
 	userID, err := apiCheckCollectionPermissions(app, r, c)
@@ -600,6 +604,7 @@ func processCollectionPermissions(app *App, cr *collectionReq, u *User, w http.R
 		}
 		return nil, err
 	}
+	c.hostName = app.cfg.App.Host
 
 	// Update CollectionRequest to reflect owner status
 	cr.isCollOwner = u != nil && u.ID == c.OwnerID
diff --git a/feed.go b/feed.go
index bf3444b..dd82c33 100644
--- a/feed.go
+++ b/feed.go
@@ -34,6 +34,7 @@ func ViewFeed(app *App, w http.ResponseWriter, req *http.Request) error {
 	if err != nil {
 		return nil
 	}
+	c.hostName = app.cfg.App.Host
 
 	if c.IsPrivate() || c.IsProtected() {
 		return ErrCollectionNotFound
diff --git a/posts.go b/posts.go
index 35cb6b9..0efa5ec 100644
--- a/posts.go
+++ b/posts.go
@@ -996,6 +996,7 @@ func fetchPost(app *App, w http.ResponseWriter, r *http.Request) error {
 		if err != nil {
 			return err
 		}
+		coll.hostName = app.cfg.App.Host
 		_, err = apiCheckCollectionPermissions(app, r, coll)
 		if err != nil {
 			return err
@@ -1056,7 +1057,7 @@ func (p *Post) processPost() PublicPost {
 
 func (p *PublicPost) CanonicalURL() string {
 	if p.Collection == nil || p.Collection.Alias == "" {
-		return hostName + "/" + p.ID
+		return p.Collection.hostName + "/" + p.ID
 	}
 	return p.Collection.CanonicalURL() + p.Slug.String
 }
@@ -1087,7 +1088,7 @@ func (p *PublicPost) ActivityObject() *activitystreams.Object {
 		if isSingleUser {
 			tagBaseURL = p.Collection.CanonicalURL() + "tag:"
 		} else {
-			tagBaseURL = fmt.Sprintf("%s/%s/tag:", hostName, p.Collection.Alias)
+			tagBaseURL = fmt.Sprintf("%s/%s/tag:", p.Collection.hostName, p.Collection.Alias)
 		}
 		for _, t := range p.Tags {
 			o.Tag = append(o.Tag, activitystreams.Tag{
@@ -1244,6 +1245,7 @@ func viewCollectionPost(app *App, w http.ResponseWriter, r *http.Request) error
 		}
 		return err
 	}
+	c.hostName = app.cfg.App.Host
 
 	// Check collection permissions
 	if c.IsPrivate() && (u == nil || u.ID != c.OwnerID) {
diff --git a/read.go b/read.go
index 13add9e..3bc91c7 100644
--- a/read.go
+++ b/read.go
@@ -52,17 +52,17 @@ type readPublication struct {
 func initLocalTimeline(app *App) {
 	app.timeline = &localTimeline{
 		postsPerPage: tlPostsPerPage,
-		m:            memo.New(app.db.FetchPublicPosts, 10*time.Minute),
+		m:            memo.New(app.FetchPublicPosts, 10*time.Minute),
 	}
 }
 
 // satisfies memo.Func
-func (db *datastore) FetchPublicPosts() (interface{}, error) {
+func (app *App) FetchPublicPosts() (interface{}, error) {
 	// Finds all public posts and posts in a public collection published during the owner's active subscription period and within the last 3 months
-	rows, err := db.Query(`SELECT p.id, alias, c.title, p.slug, p.title, p.content, p.text_appearance, p.language, p.rtl, p.created, p.updated
+	rows, err := app.db.Query(`SELECT p.id, alias, c.title, p.slug, p.title, p.content, p.text_appearance, p.language, p.rtl, p.created, p.updated
 	FROM collections c
 	LEFT JOIN posts p ON p.collection_id = c.id
-	WHERE c.privacy = 1 AND (p.created >= ` + db.dateSub(3, "month") + ` AND p.created <= ` + db.now() + ` AND pinned_position IS NULL)
+	WHERE c.privacy = 1 AND (p.created >= ` + app.db.dateSub(3, "month") + ` AND p.created <= ` + app.db.now() + ` AND pinned_position IS NULL)
 	ORDER BY p.created DESC`)
 	if err != nil {
 		log.Error("Failed selecting from posts: %v", err)
@@ -82,6 +82,8 @@ func (db *datastore) FetchPublicPosts() (interface{}, error) {
 			log.Error("[READ] Unable to scan row, skipping: %v", err)
 			continue
 		}
+		c.hostName = app.cfg.App.Host
+
 		isCollectionPost := alias.Valid
 		if isCollectionPost {
 			c.Alias = alias.String
@@ -244,6 +246,7 @@ func handlePostIDRedirect(app *App, w http.ResponseWriter, r *http.Request) erro
 	if err != nil {
 		return err
 	}
+	c.hostName = app.cfg.App.Host
 
 	// Retrieve collection information and send user to canonical URL
 	return impart.HTTPError{http.StatusFound, c.CanonicalURL() + p.Slug.String}
diff --git a/sitemap.go b/sitemap.go
index efc772b..5c37366 100644
--- a/sitemap.go
+++ b/sitemap.go
@@ -57,6 +57,7 @@ func handleViewSitemap(app *App, w http.ResponseWriter, r *http.Request) error {
 	if err != nil {
 		return err
 	}
+	c.hostName = app.cfg.App.Host
 
 	if !isSubdomain {
 		pre += alias + "/"
diff --git a/webfinger.go b/webfinger.go
index f8a0d7b..c95d88e 100644
--- a/webfinger.go
+++ b/webfinger.go
@@ -37,6 +37,7 @@ func (wfr wfResolver) FindUser(username string, host, requestHost string, r []we
 		log.Error("Unable to get blog: %v", err)
 		return nil, err
 	}
+	c.hostName = wfr.cfg.App.Host
 	if wfr.cfg.App.SingleUser {
 		// Ensure handle matches user-chosen one on single-user blogs
 		if username != c.Alias {