diff --git a/src/main/scala/gitbucket/core/service/IssuesService.scala b/src/main/scala/gitbucket/core/service/IssuesService.scala
index f3f4b96..911e3ca 100644
--- a/src/main/scala/gitbucket/core/service/IssuesService.scala
+++ b/src/main/scala/gitbucket/core/service/IssuesService.scala
@@ -18,7 +18,7 @@
   import IssuesService._
 
   def getIssue(owner: String, repository: String, issueId: String)(implicit s: Session) =
-    if (issueId forall (_.isDigit))
+    if (isInteger(issueId))
       Issues filter (_.byPrimaryKey(owner, repository, issueId.toInt)) firstOption
     else None
 
diff --git a/src/main/scala/gitbucket/core/util/StringUtil.scala b/src/main/scala/gitbucket/core/util/StringUtil.scala
index d288d49..f6e4bc0 100644
--- a/src/main/scala/gitbucket/core/util/StringUtil.scala
+++ b/src/main/scala/gitbucket/core/util/StringUtil.scala
@@ -5,6 +5,7 @@
 import ControlUtil._
 import org.apache.commons.io.input.BOMInputStream
 import org.apache.commons.io.IOUtils
+import scala.util.control.Exception._
 
 object StringUtil {
 
@@ -26,6 +27,8 @@
 
   def splitWords(value: String): Array[String] = value.split("[ \\t　]+")
 
+  def isInteger(value: String): Boolean = allCatch opt { value.toInt } map(_ => true) getOrElse(false)
+
   def escapeHtml(value: String): String =
     value.replace("&", "&amp;").replace("<", "&lt;").replace(">", "&gt;").replace("\"", "&quot;")