diff --git a/Gemfile.lock b/Gemfile.lock
index f066e6b9905cd58f3abb41cff3e7402464029edd..c251d9c649640dd1c2162bfa2cf250c1af71758a 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    gitlab-monitor (3.3.0)
+    gitlab-monitor (3.3.1)
       connection_pool (~> 2.2.1)
       pg (~> 1.1)
       quantile (~> 0.2.0)
diff --git a/lib/gitlab_monitor/version.rb b/lib/gitlab_monitor/version.rb
index 81c5116d05594c4bfe32763af06c342a69dee5df..50fd6b04eaef324911f11715712d01d5ecd6b58d 100644
--- a/lib/gitlab_monitor/version.rb
+++ b/lib/gitlab_monitor/version.rb
@@ -1,5 +1,5 @@
 module GitLab
   module Monitor
-    VERSION = "3.3.0".freeze
+    VERSION = "3.3.1".freeze
   end
 end
diff --git a/lib/gitlab_monitor/web_exporter.rb b/lib/gitlab_monitor/web_exporter.rb
index cc1e9eb94e7aaa99080bda30d5765ab7e091bcfe..02d9dde0697789d8a3eac0e432d855c568c12569 100644
--- a/lib/gitlab_monitor/web_exporter.rb
+++ b/lib/gitlab_monitor/web_exporter.rb
@@ -40,7 +40,8 @@ module GitLab
           setup_server(config[:server])
           setup_probes(config[:probes])
 
-          use MemoryKillerMiddleware, config[:server][:memory_threshold] || 1024
+          memory_threshold = (config[:server] && config[:server][:memory_threshold]) || 1024
+          use MemoryKillerMiddleware, memory_threshold
         end
 
         def setup_server(config)