diff --git a/src/main/scala/gitbucket/core/service/AccessTokenService.scala b/src/main/scala/gitbucket/core/service/AccessTokenService.scala
index 102240d..8976ce2 100644
--- a/src/main/scala/gitbucket/core/service/AccessTokenService.scala
+++ b/src/main/scala/gitbucket/core/service/AccessTokenService.scala
@@ -5,13 +5,13 @@
 import gitbucket.core.model.{AccessToken, Account}
 import gitbucket.core.util.StringUtil
 
-import scala.util.Random
+import java.security.SecureRandom
 
 trait AccessTokenService {
 
   def makeAccessTokenString: String = {
     val bytes = new Array[Byte](20)
-    Random.nextBytes(bytes)
+    AccessTokenService.secureRandom.nextBytes(bytes)
     bytes.map("%02x".format(_)).mkString
   }
 
@@ -55,4 +55,6 @@
 
 }
 
-object AccessTokenService extends AccessTokenService
+object AccessTokenService extends AccessTokenService {
+  private val secureRandom = new SecureRandom()
+}