diff --git a/build.sbt b/build.sbt
index c2e0b2e2c5..503f605e3d 100644
--- a/build.sbt
+++ b/build.sbt
@@ -78,7 +78,7 @@ val scalafixCoreDep =
     .scalafixVersion % ScalafixConfig
 
 val testDependencies = Seq(
-  "org.scalamock" %% "scalamock" % "5.2.0",
+  "org.scalamock" %% "scalamock" % "6.0.0",
   "org.scalatest" %% "scalatest" % "3.2.19",
   "org.scalatestplus" %% "scalacheck-1-14" % "3.2.2.0",
   // テスト用のTestSchedulerを使うため