diff --git a/app/assets/javascripts/diffs/store/actions.js b/app/assets/javascripts/diffs/store/actions.js
index ee319990290481cf70e0b01bd69b0b9df7da12c1..8c72971682dd1cecda1a12b3143aaf6b0c585919 100644
--- a/app/assets/javascripts/diffs/store/actions.js
+++ b/app/assets/javascripts/diffs/store/actions.js
@@ -185,11 +185,11 @@ export const fetchDiffFilesMeta = ({ commit, state }) => {
     .get(mergeUrlParams(urlParams, state.endpointMetadata))
     .then(({ data }) => {
       const strippedData = { ...data };
-
       delete strippedData.diff_files;
+
       commit(types.SET_LOADING, false);
       commit(types.SET_MERGE_REQUEST_DIFFS, data.merge_request_diffs || []);
-      commit(types.SET_DIFF_DATA, strippedData);
+      commit(types.SET_DIFF_METADATA, strippedData);
 
       worker.postMessage(prepareDiffData(data, state.diffFiles));
 
diff --git a/app/assets/javascripts/diffs/store/mutation_types.js b/app/assets/javascripts/diffs/store/mutation_types.js
index 251840287993ee7136e53c2c9e45297ce024102f..30097239aaa230d8a238cae83794268ad593fff2 100644
--- a/app/assets/javascripts/diffs/store/mutation_types.js
+++ b/app/assets/javascripts/diffs/store/mutation_types.js
@@ -3,7 +3,7 @@ export const SET_LOADING = 'SET_LOADING';
 export const SET_BATCH_LOADING = 'SET_BATCH_LOADING';
 export const SET_RETRIEVING_BATCHES = 'SET_RETRIEVING_BATCHES';
 
-export const SET_DIFF_DATA = 'SET_DIFF_DATA';
+export const SET_DIFF_METADATA = 'SET_DIFF_METADATA';
 export const SET_DIFF_DATA_BATCH = 'SET_DIFF_DATA_BATCH';
 export const SET_DIFF_FILES = 'SET_DIFF_FILES';
 
diff --git a/app/assets/javascripts/diffs/store/mutations.js b/app/assets/javascripts/diffs/store/mutations.js
index 69ae3f705e3326c1ba543f6d4833132c43aacafa..90940d8222637f3dc477d40952f161fd9abb67c3 100644
--- a/app/assets/javascripts/diffs/store/mutations.js
+++ b/app/assets/javascripts/diffs/store/mutations.js
@@ -66,17 +66,10 @@ export default {
     updateDiffFilesInState(state, files);
   },
 
-  [types.SET_DIFF_DATA](state, data) {
-    let files = state.diffFiles;
-
-    if (window.location.search.indexOf('diff_id') !== -1 && data.diff_files) {
-      files = prepareDiffData(data, files);
-    }
-
+  [types.SET_DIFF_METADATA](state, data) {
     Object.assign(state, {
       ...convertObjectPropsToCamelCase(data),
     });
-    updateDiffFilesInState(state, files);
   },
 
   [types.SET_DIFF_DATA_BATCH](state, data) {
diff --git a/spec/frontend/diffs/store/actions_spec.js b/spec/frontend/diffs/store/actions_spec.js
index cd79f9489260f5fd14f0ae4908be2d02ae77dd58..fef7676e7950f24b4ccb1c96c1dfdf3b43598fc1 100644
--- a/spec/frontend/diffs/store/actions_spec.js
+++ b/spec/frontend/diffs/store/actions_spec.js
@@ -249,7 +249,7 @@ describe('DiffsStoreActions', () => {
           { type: types.SET_LOADING, payload: true },
           { type: types.SET_LOADING, payload: false },
           { type: types.SET_MERGE_REQUEST_DIFFS, payload: diffMetadata.merge_request_diffs },
-          { type: types.SET_DIFF_DATA, payload: noFilesData },
+          { type: types.SET_DIFF_METADATA, payload: noFilesData },
         ],
         [],
         () => {
diff --git a/spec/frontend/diffs/store/mutations_spec.js b/spec/frontend/diffs/store/mutations_spec.js
index c061c5c25906c5b281f0bacef005d0062bcd830e..13e7cad835dc0d9621eb4096dd39fe37dbc5df25 100644
--- a/spec/frontend/diffs/store/mutations_spec.js
+++ b/spec/frontend/diffs/store/mutations_spec.js
@@ -67,24 +67,24 @@ describe('DiffsStoreMutations', () => {
     });
   });
 
-  describe('SET_DIFF_DATA', () => {
-    it('should not modify the existing state', () => {
+  describe('SET_DIFF_METADATA', () => {
+    it('should overwrite state with the camelCased data that is passed in', () => {
       const state = {
-        diffFiles: [
-          {
-            content_sha: diffFileMockData.content_sha,
-            file_hash: diffFileMockData.file_hash,
-            [INLINE_DIFF_LINES_KEY]: [],
-          },
-        ],
+        diffFiles: [],
       };
       const diffMock = {
         diff_files: [diffFileMockData],
       };
+      const metaMock = {
+        other_key: 'value',
+      };
 
-      mutations[types.SET_DIFF_DATA](state, diffMock);
+      mutations[types.SET_DIFF_METADATA](state, diffMock);
+      expect(state.diffFiles[0]).toEqual(diffFileMockData);
 
-      expect(state.diffFiles[0][INLINE_DIFF_LINES_KEY]).toEqual([]);
+      mutations[types.SET_DIFF_METADATA](state, metaMock);
+      expect(state.diffFiles[0]).toEqual(diffFileMockData);
+      expect(state.otherKey).toEqual('value');
     });
   });