diff --git a/provider/sqlite/sqlite.go b/provider/sqlite/sqlite.go
index 069d0e99..de76f1a4 100644
--- a/provider/sqlite/sqlite.go
+++ b/provider/sqlite/sqlite.go
@@ -25,6 +25,7 @@ CREATE TABLE IF NOT EXISTS alerts (
 	updated_at  timestamp,
 	timeout     integer
 );
+CREATE INDEX IF NOT EXISTS fingerprint    ON alerts (fingerprint);
 CREATE INDEX IF NOT EXISTS alerts_start   ON alerts (starts_at);
 CREATE INDEX IF NOT EXISTS alerts_end     ON alerts (ends_at);
 CREATE INDEX IF NOT EXISTS alerts_updated ON alerts (updated_at);
@@ -600,6 +601,9 @@ func (s *Silences) Set(sil *types.Silence) (uint64, error) {
 
 // Del implements the Silences interface.
 func (s *Silences) Del(sid uint64) error {
+	dbmtx.Lock()
+	defer dbmtx.Unlock()
+
 	tx, err := s.db.Begin()
 	if err != nil {
 		return err
diff --git a/web.go b/web.go
index fdfc8666..6e203849 100644
--- a/web.go
+++ b/web.go
@@ -17,6 +17,7 @@ import (
 	"bytes"
 	"io"
 	"net/http"
+	_ "net/http/pprof" // Comment this line to disable pprof endpoint.
 	"path/filepath"
 
 	"github.com/prometheus/client_golang/prometheus"
@@ -67,4 +68,7 @@ func RegisterWeb(r *route.Router) {
 	r.Get("/", ihf("index", func(w http.ResponseWriter, req *http.Request) {
 		serveAsset(w, req, "ui/app/index.html")
 	}))
+
+	r.Get("/debug/*subpath", http.DefaultServeMux.ServeHTTP)
+	r.Post("/debug/*subpath", http.DefaultServeMux.ServeHTTP)
 }