diff --git a/app/models/node.rb b/app/models/node.rb
index 8b09ffef7..230c83882 100644
--- a/app/models/node.rb
+++ b/app/models/node.rb
@@ -97,7 +97,7 @@ class Node < ActiveRecord::Base
 
     user_display_name_cache = {} if user_display_name_cache.nil?
 
-    if user_display_name_cache and user_display_name_cache[self.user_id]
+    if user_display_name_cache and user_display_name_cache.key?(self.user_id)
       # use the cache if available
     elsif self.user.data_public?
       user_display_name_cache[self.user_id] = self.user.display_name
diff --git a/app/models/segment.rb b/app/models/segment.rb
index aa4e07887..bdb807d93 100644
--- a/app/models/segment.rb
+++ b/app/models/segment.rb
@@ -88,7 +88,7 @@ class Segment < ActiveRecord::Base
 
     user_display_name_cache = {} if user_display_name_cache.nil?
 
-    if user_display_name_cache and user_display_name_cache[self.user_id]
+    if user_display_name_cache and user_display_name_cache.key?(self.user_id)
       # use the cache if available
     elsif self.user.data_public?
       user_display_name_cache[self.user_id] = self.user.display_name
diff --git a/app/models/way.rb b/app/models/way.rb
index fe16e98c3..c6316d330 100644
--- a/app/models/way.rb
+++ b/app/models/way.rb
@@ -61,7 +61,7 @@ class Way < ActiveRecord::Base
 
     user_display_name_cache = {} if user_display_name_cache.nil?
     
-    if user_display_name_cache and user_display_name_cache[self.user_id]
+    if user_display_name_cache and user_display_name_cache.key?(self.user_id)
       # use the cache if available
     elsif self.user.data_public?
       user_display_name_cache[self.user_id] = self.user.display_name