diff --git a/services/filestore/test/unit/js/FileConverterTests.js b/services/filestore/test/unit/js/FileConverterTests.js
index 1b548d592e..89faacd1d1 100644
--- a/services/filestore/test/unit/js/FileConverterTests.js
+++ b/services/filestore/test/unit/js/FileConverterTests.js
@@ -29,10 +29,8 @@ describe('FileConverter', function() {
           err() {}
         },
         'metrics-sharelatex': {
-          inc() {},
-          Timer() {
-            return { done() {} }
-          }
+          inc: sinon.stub(),
+          Timer: sinon.stub().returns({ done: sinon.stub() })
         },
         'settings-sharelatex': (this.Settings = {
           commands: {
diff --git a/services/filestore/test/unit/js/LocalFileWriterTests.js b/services/filestore/test/unit/js/LocalFileWriterTests.js
index e7ea993ab9..04cc2fb049 100644
--- a/services/filestore/test/unit/js/LocalFileWriterTests.js
+++ b/services/filestore/test/unit/js/LocalFileWriterTests.js
@@ -48,10 +48,8 @@ describe('LocalFileWriter', function() {
         },
         'settings-sharelatex': this.settings,
         'metrics-sharelatex': {
-          inc() {},
-          Timer() {
-            return { done() {} }
-          }
+          inc: sinon.stub(),
+          Timer: sinon.stub().returns({ done: sinon.stub() })
         }
       }
     })