diff --git a/config.ru b/config.ru
index fc414df..6084517 100644
--- a/config.ru
+++ b/config.ru
@@ -1,4 +1,5 @@
 require 'oj'
+Oj.default_options = { :mode => :strict }
 opts = Oj.load( File.read('config.json') )
 
 # prepare the logger
diff --git a/optica.rb b/optica.rb
index 8185ddc..c599c1b 100644
--- a/optica.rb
+++ b/optica.rb
@@ -91,7 +91,7 @@ def get_nodes(request, fields_to_include=nil)
 
   post '/' do
     begin
-      data = Oj.load request.body.read
+      data = Oj.load(request.body.read, :mode => :strict)
     rescue JSON::ParserError
       data = {}
     end
diff --git a/store.rb b/store.rb
index 354ff44..395b93f 100644
--- a/store.rb
+++ b/store.rb
@@ -174,7 +174,7 @@ def load_instances_from_leader
       uri = "http://localhost:%d/store" % @opts['split_mode_store_port']
       res = open(uri, :read_timeout => @opts['split_mode_http_timeout'])
 
-      remote_store = Oj.load res.read
+      remote_store = Oj.load(res.read, :mode => :strict)
       [ remote_store['inst'], remote_store['idx'] ]
     rescue OpenURI::HTTPError, Errno::ECONNREFUSED, Net::ReadTimeout => e
       @log.error "Error loading store from #{uri}: #{e.inspect}; will retry after #{@opts['split_mode_retry_delay']}"
@@ -322,7 +322,7 @@ def get_node(node)
         @zk.get(node)
       end
       STATSD.time('optica.json.parse') do
-        Oj.load(data)
+        Oj.load(data, :mode => :strict)
       end
     rescue ZK::Exceptions::NoNode
       @log.info "node #{node} disappeared"