diff --git a/internal/http/handlers.go b/internal/http/handlers.go
index d09e7a3..99f2a0a 100644
--- a/internal/http/handlers.go
+++ b/internal/http/handlers.go
@@ -67,7 +67,7 @@ func (h *UploadHandlers) Upload(w http.ResponseWriter, r *http.Request) {
 
 	if err := r.ParseMultipartForm(fMaxSizeBytes); err != nil {
 		log.Println("failed to parse upload form:", err)
-		http.Error(w, "Failed to parse upload form.", http.StatusExpectationFailed)
+		Error(w, r, http.StatusExpectationFailed, "Failed to parse upload form.")
 		return
 	}
 
@@ -75,8 +75,7 @@ func (h *UploadHandlers) Upload(w http.ResponseWriter, r *http.Request) {
 	if err != nil {
 		log.Println("failed to open incoming file:", err)
 		w.WriteHeader(http.StatusInternalServerError)
-		web.Error50x(utils.MainSite(r.Host), http.StatusInternalServerError,
-			"Error reading an incoming file.", w)
+		Error(w, r, http.StatusInternalServerError, "Error reading an incoming file.")
 		return
 	}
 	defer func() {
@@ -95,8 +94,7 @@ func (h *UploadHandlers) Upload(w http.ResponseWriter, r *http.Request) {
 	s256 := sha256.New()
 	if _, err := io.Copy(s256, f); err != nil {
 		log.Println("failed to compute a SHA-256 hash:", err)
-		web.Error50x(utils.MainSite(r.Host), http.StatusInternalServerError,
-			"A hash for the file cannot be computed.", w)
+		Error(w, r, http.StatusInternalServerError, "A hash for the file cannot be computed.")
 		return
 	}
 
@@ -113,8 +111,7 @@ func (h *UploadHandlers) Upload(w http.ResponseWriter, r *http.Request) {
 		fDst, err := os.Create(fPath)
 		if err != nil {
 			log.Println("failed to open file for writing", err)
-			web.Error50x(utils.MainSite(r.Host), http.StatusInternalServerError,
-				"File cannot be written.", w)
+			Error(w, r, http.StatusInternalServerError, "File cannot be written.")
 			return
 		}
 		defer fDst.Close()
@@ -130,8 +127,7 @@ func (h *UploadHandlers) Upload(w http.ResponseWriter, r *http.Request) {
 		_, err = io.Copy(fDst, f)
 		if err != nil {
 			log.Println("failed to copy uploaded file to destination:", err)
-			web.Error50x(utils.MainSite(r.Host), http.StatusInternalServerError,
-				"Failed to copy uploaded file to the storage.", w)
+			Error(w, r, http.StatusInternalServerError, "Failed to copy uploaded file to the storage.")
 			return
 		}
 
@@ -167,7 +163,7 @@ func (h *UploadHandlers) Download(w http.ResponseWriter, r *http.Request) {
 
 	stat, err := os.Stat(path)
 	if os.IsNotExist(err) {
-		NotFound(w, r)
+		Error(w, r, http.StatusNotFound, "")
 		return
 	}
 
@@ -178,8 +174,7 @@ func (h *UploadHandlers) Download(w http.ResponseWriter, r *http.Request) {
 	fd, err := os.Open(path)
 	if err != nil {
 		log.Println("failed to open file to read:", err)
-		web.Error50x(utils.MainSite(r.Host), http.StatusInternalServerError,
-			"Failed to open file to read.", w)
+		Error(w, r, http.StatusInternalServerError, "Failed to open file to read.")
 		return
 	}
 	defer fd.Close()
@@ -204,15 +199,14 @@ func (h *UploadHandlers) Delete(w http.ResponseWriter, r *http.Request) {
 
 	_, err := os.Stat(path)
 	if os.IsNotExist(err) {
-		NotFound(w, r)
+		Error(w, r, http.StatusNotFound, "")
 		return
 	}
 
 	err = os.Remove(path)
 	if err != nil {
 		log.Println("failed to remove a file:", err)
-		web.Error50x(utils.MainSite(r.Host), http.StatusInternalServerError,
-			"Failed to remove a file.", w)
+		Error(w, r, http.StatusInternalServerError, "Failed to remove a file.")
 		return
 	}