diff --git a/app/assets/javascripts/mumuki_laboratory/application/bridge.js b/app/assets/javascripts/mumuki_laboratory/application/bridge.js
index 7a8fa7a34..7e2f9efe3 100644
--- a/app/assets/javascripts/mumuki_laboratory/application/bridge.js
+++ b/app/assets/javascripts/mumuki_laboratory/application/bridge.js
@@ -1,25 +1,36 @@
 /**
- * @typedef {{status: SubmissionStatus, test_results: [{status: SubmissionStatus, title: string}]}} SubmissionClientResult
+ * @typedef {"errored"|"failed"|"passed_with_warnings"|"passed"|"pending"|"aborted"} SubmissionStatus
  */
 
 /**
  * @typedef {{
  *  status: SubmissionStatus,
- *  class_for_progress_list_item?: string,
- *  guide_finished_by_solution?: boolean
- * }} SubmissionResult
+ *  test_results: [{status: SubmissionStatus, title: string}]
+ * }} SubmissionClientResult
  */
 
 /**
- * @typedef {{solution: object, client_result?: SubmissionClientResult}} Submission
+ * @typedef {{
+  *  status: SubmissionStatus,
+  *  class_for_progress_list_item?: string,
+  *  guide_finished_by_solution?: boolean
+  * }} SubmissionResult
+  */
+
+/**
+ * @typedef {object} Solution
  */
 
 /**
- * @typedef {"errored"|"failed"|"passed_with_warnings"|"passed"|"pending"|"aborted"} SubmissionStatus
+ * @typedef {{
+ *  "solution[content]"?:string,
+ *  solution?: Solution,
+ *  client_result?: SubmissionClientResult
+ * }} Submission
  */
 
 /**
- * @typedef {{content?: {solution: object}, result?: SubmissionResult}} SubmissionAndResult
+ * @typedef {{submission?: Submission, result?: SubmissionResult}} SubmissionAndResult
  */
 
 mumuki.bridge = (() => {
@@ -51,26 +62,18 @@ mumuki.bridge = (() => {
      */
     _submitSolution(submission) {
       const lastSubmission = mumuki.SubmissionsStore.getCachedResultFor(mumuki.currentExerciseId, submission);
-      if(lastSubmission){
+      if (lastSubmission) {
         return $.Deferred().resolve(lastSubmission);
       } else {
         return this._sendNewSolution(submission).done((result) => {
-          mumuki.SubmissionsStore.setLastSubmission(mumuki.currentExerciseId, this._buildLastSubmission(submission, result));
+          mumuki.SubmissionsStore.setLastSubmission(mumuki.currentExerciseId, {submission, result});
         });
       }
     }
 
-    /**
-     * @param {Submission} submission
-     * @param {SubmissionResult} result
-     * @returns {SubmissionAndResult}
-     */
-    _buildLastSubmission(submission, result) {
-      return { content: {solution: submission.solution}, result: result }
-    }
-
     /**
      * @param {Submission} submission the submission object
+     * @returns {JQuery.Promise<SubmissionResult>}
      */
     _sendNewSolution(submission){
       var token = new mumuki.CsrfToken();
diff --git a/app/assets/javascripts/mumuki_laboratory/application/submissions-store.js b/app/assets/javascripts/mumuki_laboratory/application/submissions-store.js
index 85d8e20e1..f1ed2d703 100644
--- a/app/assets/javascripts/mumuki_laboratory/application/submissions-store.js
+++ b/app/assets/javascripts/mumuki_laboratory/application/submissions-store.js
@@ -1,4 +1,4 @@
-(() => {
+mumuki.SubmissionsStore = (() => {
   const SubmissionsStore = new class {
     /**
      * @param {number} exerciseId
@@ -14,35 +14,62 @@
      * @returns {SubmissionAndResult}
      */
     getLastSubmission(exerciseId) {
-      const submission = window.localStorage.getItem(this._keyFor(exerciseId));
-      if (!submission) return null;
-      return JSON.parse(submission);
+      const submissionAndResult = window.localStorage.getItem(this._keyFor(exerciseId));
+      if (!submissionAndResult) return null;
+      return JSON.parse(submissionAndResult);
     }
 
     /**
      * @param {number} exerciseId
-     * @param {SubmissionAndResult} submission
+     * @param {SubmissionAndResult} submissionAndResult
      */
-    setLastSubmission(exerciseId, submission) {
-      window.localStorage.setItem(this._keyFor(exerciseId), this._asString(submission));
+    setLastSubmission(exerciseId, submissionAndResult) {
+      window.localStorage.setItem(this._keyFor(exerciseId), this._asString(submissionAndResult));
     }
 
     /**
+     * Retrieves the last cached, non-aborted result for the given submission
      *
      * @param {number} exerciseId
-     * @param {*} newSolution
-     * @returns {SubmissionResult}
+     * @param {Submission} submission
+     * @returns {SubmissionResult} the cached result for this submission
      */
-    getCachedResultFor(exerciseId, newSolution) {
+    getCachedResultFor(exerciseId, submission) {
       const lastSubmission = this.getLastSubmission(exerciseId);
       if (!lastSubmission
           || lastSubmission.result.status === 'aborted'
-          || !this._solutionEquals(lastSubmission, newSolution)) {
+          || !this.submissionSolutionEquals(lastSubmission.submission, submission)) {
         return null;
       }
       return lastSubmission.result;
     }
 
+     /**
+     * Extract the submission's solution content
+     *
+     * @param {Submission} submission
+     * @returns {string}
+     */
+    submissionSolutionContent(submission) {
+      if (submission.solution) {
+        return submission.solution.content;
+      } else {
+        return submission['solution[content]'];
+      }
+    }
+
+    /**
+     * Compares two solutions to determine if they are equivalent
+     * from the point of view of the code evaluation
+     *
+     * @param {Submission} one
+     * @param {Submission} other
+     * @returns {boolean}
+     */
+    submissionSolutionEquals(one, other) {
+      return this.submissionSolutionContent(one) === this.submissionSolutionContent(other);
+    }
+
     // private API
 
     _asString(object) {
@@ -52,10 +79,7 @@
     _keyFor(exerciseId) {
       return `/exercise/${exerciseId}/submission`;
     }
-
-    _solutionEquals(submission, solution) {
-      return this._asString(submission.content) === this._asString(solution);
-    }
   };
-  mumuki.SubmissionsStore = SubmissionsStore;
+
+  return SubmissionsStore;
 })();