diff --git a/app/models/issue.rb b/app/models/issue.rb
index 95e5a4f24..cfad63a91 100644
--- a/app/models/issue.rb
+++ b/app/models/issue.rb
@@ -1018,7 +1018,9 @@ class Issue < ApplicationRecord
 
   # Returns true if this issue is blocked by another issue that is still open
   def blocked?
-    !relations_to.detect {|ir| ir.relation_type == 'blocks' && !ir.issue_from.closed?}.nil?
+    return false if relations.empty?
+
+    relations_to.where(relation_type: IssueRelation::TYPE_BLOCKS).any? {|ir| !ir.issue_to.closed?}
   end
 
   # Returns true if this issue can be closed and if not, returns false and populates the reason
@@ -1348,7 +1350,9 @@ class Issue < ApplicationRecord
 
   # Returns an array of issues that duplicate this one
   def duplicates
-    relations_to.select {|r| r.relation_type == IssueRelation::TYPE_DUPLICATES}.collect {|r| r.issue_from}
+    return [] if relations.empty?
+
+    relations_to.where(relation_type: IssueRelation::TYPE_DUPLICATES).collect(&:issue_from)
   end
 
   # Returns the due date or the target due date if any