diff --git a/lib/metrics.rb b/lib/metrics.rb
index c9e6a8944c..9418e7eecd 100644
--- a/lib/metrics.rb
+++ b/lib/metrics.rb
@@ -48,4 +48,22 @@ def benchmark_and_record_metric(type, event, labels, description)
     elapsed_time_seconds = Process.clock_gettime(Process::CLOCK_MONOTONIC) - start
     record_metric(type, event, elapsed_time_seconds, labels, description)
   end
+
+  class Prometheus
+    include Singleton
+
+    def initialize
+      @client = PrometheusExporter::Client.default
+      @collectors = {}
+    end
+
+    def register(type, name, description = nil)
+      @collectors[name] ||= @client.register(type, name, description)
+      self
+    end
+
+    def observe(name, value, labels = {})
+      @collectors[name].observe(value, labels)
+    end
+  end
 end
diff --git a/lib/prometheus.rb b/lib/prometheus.rb
deleted file mode 100644
index 1e67a1aaec..0000000000
--- a/lib/prometheus.rb
+++ /dev/null
@@ -1,18 +0,0 @@
-require "prometheus_exporter/client"
-class Prometheus
-  include Singleton
-
-  def initialize
-    @client = PrometheusExporter::Client.default
-    @collectors = {}
-  end
-
-  def register(type, name, description = nil)
-    @collectors[name] ||= @client.register(type, name, description)
-    self
-  end
-
-  def observe(name, value, labels = {})
-    @collectors[name].observe(value, labels)
-  end
-end