diff --git a/cmd/mttilemapper/main.go b/cmd/mttilemapper/main.go
index 87fea0c..e5d91d7 100644
--- a/cmd/mttilemapper/main.go
+++ b/cmd/mttilemapper/main.go
@@ -10,6 +10,8 @@ import (
 	"image"
 	"image/color"
 	"log"
+	"os"
+	"runtime/pprof"
 
 	"bitbucket.org/s_l_teichmann/mtsatellite/common"
 )
@@ -24,6 +26,7 @@ func main() {
 		outfile              string
 		shaded               bool
 		transparent          bool
+		cpuProfile           string
 	)
 
 	flag.IntVar(&port, "port", 6379, "port to of mtredisalize server")
@@ -43,9 +46,19 @@ func main() {
 	flag.StringVar(&outfile, "o", "out.png", "image file of result (shorthand)")
 	flag.BoolVar(&shaded, "shaded", true, "draw relief")
 	flag.BoolVar(&transparent, "transparent", false, "render transparent blocks")
+	flag.StringVar(&cpuProfile, "cpuprofile", "", "write cpu profile to file")
 
 	flag.Parse()
 
+	if cpuProfile != "" {
+		f, err := os.Create(cpuProfile)
+		if err != nil {
+			log.Fatal(err)
+		}
+		pprof.StartCPUProfile(f)
+		defer pprof.StopCPUProfile()
+	}
+
 	var err error
 	var colors *common.Colors