diff --git a/go.mod b/go.mod
index 94bf2f8..8cdc247 100644
--- a/go.mod
+++ b/go.mod
@@ -1,10 +1,7 @@
 module github.com/cybozu-go/golang-custom-analyzer
 
-go 1.19
+go 1.20
 
-require golang.org/x/tools v0.11.1
+require golang.org/x/tools v0.19.0
 
-require (
-	golang.org/x/mod v0.12.0 // indirect
-	golang.org/x/sys v0.10.0 // indirect
-)
+require golang.org/x/mod v0.16.0 // indirect
diff --git a/go.sum b/go.sum
index b938524..99fac8c 100644
--- a/go.sum
+++ b/go.sum
@@ -1,7 +1,5 @@
-golang.org/x/mod v0.12.0 h1:rmsUpXtvNzj340zd98LZ4KntptpfRHwpFOHG188oHXc=
-golang.org/x/mod v0.12.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
-golang.org/x/sync v0.3.0 h1:ftCYgMx6zT/asHUrPw8BLLscYtGznsLAnjq5RH9P66E=
-golang.org/x/sys v0.10.0 h1:SqMFp9UcQJZa+pmYuAKjd9xq1f0j5rLcDIk0mj4qAsA=
-golang.org/x/sys v0.10.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/tools v0.11.1 h1:ojD5zOW8+7dOGzdnNgersm8aPfcDjhMp12UfG93NIMc=
-golang.org/x/tools v0.11.1/go.mod h1:anzJrxPjNtfgiYQYirP2CPGzGLxrH2u2QBhn6Bf3qY8=
+golang.org/x/mod v0.16.0 h1:QX4fJ0Rr5cPQCF7O9lh9Se4pmwfwskqZfq5moyldzic=
+golang.org/x/mod v0.16.0/go.mod h1:hTbmBsO62+eylJbnUtE2MGJUyE7QWk4xUqPFrRgJ+7c=
+golang.org/x/sync v0.6.0 h1:5BMeUDZ7vkXGfEr1x9B4bRcTH4lpkTkpdh0T/J+qjbQ=
+golang.org/x/tools v0.19.0 h1:tfGCXNR1OsFG+sVdLAitlpjAvD/I6dHDKnYrpEZUHkw=
+golang.org/x/tools v0.19.0/go.mod h1:qoJWxmGSIBmAeriMx19ogtrEPrGtDbPK634QFIcLAhc=