diff --git a/lib/acts_as_taggable_on/acts_as_taggable_on/core.rb b/lib/acts_as_taggable_on/acts_as_taggable_on/core.rb
index 1d32b375c..3a0a8b922 100644
--- a/lib/acts_as_taggable_on/acts_as_taggable_on/core.rb
+++ b/lib/acts_as_taggable_on/acts_as_taggable_on/core.rb
@@ -110,7 +110,7 @@ def tagged_with(tags, options = {})
             joins <<  "JOIN #{ActsAsTaggableOn::Tagging.table_name}" +
                       "  ON #{ActsAsTaggableOn::Tagging.table_name}.taggable_id = #{quote}#{table_name}#{quote}.#{primary_key}" +
                       " AND #{ActsAsTaggableOn::Tagging.table_name}.taggable_type = #{quote_value(base_class.name)}" +
-                      " AND #{ActsAsTaggableOn::Tagging.table_name}.tagger_id = #{owned_by.id}" +
+                      " AND #{ActsAsTaggableOn::Tagging.table_name}.tagger_id = #{quote_value(owned_by.id)}" +
                       " AND #{ActsAsTaggableOn::Tagging.table_name}.tagger_type = #{quote_value(owned_by.class.base_class.to_s)}"
           end
 
@@ -138,7 +138,7 @@ def tagged_with(tags, options = {})
           tagging_join << " AND " + sanitize_sql(["#{taggings_alias}.context = ?", context.to_s]) if context
 
           # don't need to sanitize sql, map all ids and join with OR logic
-          conditions << tags.map { |t| "#{taggings_alias}.tag_id = '#{t.id}'" }.join(" OR ")
+          conditions << tags.map { |t| "#{taggings_alias}.tag_id = #{quote_value(t.id)}" }.join(" OR ")
           select_clause = "DISTINCT #{table_name}.*" unless context and tag_types.one?
 
           if owned_by
@@ -161,7 +161,7 @@ def tagged_with(tags, options = {})
             tagging_join  = "JOIN #{ActsAsTaggableOn::Tagging.table_name} #{taggings_alias}" +
                             "  ON #{taggings_alias}.taggable_id = #{quote}#{table_name}#{quote}.#{primary_key}" +
                             " AND #{taggings_alias}.taggable_type = #{quote_value(base_class.name)}" +
-                            " AND #{taggings_alias}.tag_id = '#{tag.id}'"
+                            " AND #{taggings_alias}.tag_id = #{quote_value(tag.id)}"
 
             tagging_join << " AND " + sanitize_sql(["#{taggings_alias}.context = ?", context.to_s]) if context