diff --git a/go.mod b/go.mod
index b7484c9..cd8f6a5 100644
--- a/go.mod
+++ b/go.mod
@@ -4,7 +4,8 @@ go 1.13
 
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
-	github.com/google/go-cmp v0.6.0 // indirect
+	github.com/edsrzf/mmap-go v1.2.0
+	github.com/google/go-cmp v0.6.0
 	github.com/jessevdk/go-flags v1.5.0
 	github.com/kr/pretty v0.1.0 // indirect
 	github.com/rs/zerolog v1.26.1
@@ -12,6 +13,4 @@ require (
 	golang.org/x/sys v0.1.0 // indirect
 	gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 // indirect
 	gopkg.in/yaml.v3 v3.0.0
-	launchpad.net/gocheck v0.0.0-20140225173054-000000000087 // indirect
-	launchpad.net/gommap v0.0.0-20121012075617-000000000015
 )
diff --git a/go.sum b/go.sum
index 9013113..f1b694a 100644
--- a/go.sum
+++ b/go.sum
@@ -2,6 +2,8 @@ github.com/coreos/go-systemd/v22 v22.3.2/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSV
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/edsrzf/mmap-go v1.2.0 h1:hXLYlkbaPzt1SaQk+anYwKSRNhufIDCchSPkUD6dD84=
+github.com/edsrzf/mmap-go v1.2.0/go.mod h1:19H/e8pUPLicwkyNgOykDXkJ9F0MHE+Z52B8EIth78Q=
 github.com/godbus/dbus/v5 v5.0.4/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
@@ -38,6 +40,7 @@ golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20210320140829-1e4c9ba3b0c4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210809222454-d867a43fc93e/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20211216021012-1d35b9e2eb4e/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.1.0 h1:kunALQeHf1/185U1i0GOB/fy1IPRDDpuoOOqRReG57U=
 golang.org/x/sys v0.1.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
@@ -56,7 +59,3 @@ gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.0 h1:hjy8E9ON/egN1tAYqKb61G10WtihqetD4sz2H+8nIeA=
 gopkg.in/yaml.v3 v3.0.0/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
-launchpad.net/gocheck v0.0.0-20140225173054-000000000087 h1:Izowp2XBH6Ya6rv+hqbceQyw/gSGoXfH/UPoTGduL54=
-launchpad.net/gocheck v0.0.0-20140225173054-000000000087/go.mod h1:hj7XX3B/0A+80Vse0e+BUHsHMTEhd0O4cpUHr/e/BUM=
-launchpad.net/gommap v0.0.0-20121012075617-000000000015 h1:ROjpWoAwfoub5UmgCuZwFvM/kWU+UFfuBXbJ6lz/awU=
-launchpad.net/gommap v0.0.0-20121012075617-000000000015/go.mod h1:+rB9VlRTGlxdpc/nkCoOe0Qxgn/pyVwo9lGtVndZbOo=
diff --git a/searcher.go b/searcher.go
index 9993c32..83a2ea7 100644
--- a/searcher.go
+++ b/searcher.go
@@ -17,7 +17,7 @@ import (
 	"regexp"
 
 	"github.com/rs/zerolog"
-	"launchpad.net/gommap"
+	mmap "github.com/edsrzf/mmap-go"
 )
 
 var (
@@ -101,7 +101,7 @@ func NewSearcherOptions(path string, opt SearcherOptions) (*Searcher, error) {
 	}
 
 	// Mmap file
-	mmap, err := gommap.Map(rdr.Fd(), gommap.PROT_READ, gommap.MAP_PRIVATE)
+	mmap, err := mmap.Map(rdr, mmap.RDONLY, 0)
 	if err != nil {
 		return nil, err
 	}