diff --git a/pmtiles/makesync.go b/pmtiles/makesync.go
index 8236cbe..f383f0d 100644
--- a/pmtiles/makesync.go
+++ b/pmtiles/makesync.go
@@ -14,6 +14,7 @@ import (
 	"log"
 	"os"
 	"runtime"
+	"runtime/pprof"
 	"strconv"
 	"strings"
 	"time"
@@ -38,6 +39,13 @@ type Syncline struct {
 }
 
 func Makesync(logger *log.Logger, cli_version string, file string, block_size_kb int, checksum string) error {
+	f, err := os.Create("makesync.profile")
+	if err != nil {
+		log.Fatal("could not create CPU profile: ", err)
+	}
+	defer f.Close()
+	pprof.StartCPUProfile(f)
+	defer pprof.StopCPUProfile()
 	ctx := context.Background()
 	start := time.Now()